Plasma soluble cluster of differentiation 147 levels are increased in breast cancer patients and associated with lymph node metastasis and chemoresistance

Hong Kong Med J 2018 Jun;24(3):252–60 | Epub 25 May 2018
DOI: 10.12809/hkmj176865
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Plasma soluble cluster of differentiation 147 levels are increased in breast cancer patients and associated with lymph node metastasis and chemoresistance
YH Kuang, PhD1; YJ Liu, MSc2; LL Tang, PhD2; SM Wang, PhD2; GJ Yan, BSc2; LQ Liao, PhD2
1 Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China
2 Department of Breast Surgery, Hunan Clinical Meditech Research Center for Breast Cancer, Xiangya Hospital, Central South University, Changsha, Hunan, China
 
Corresponding author: Dr LQ Liao (aq301981@163.com)
 
 Full paper in PDF
 
Abstract
Introduction: Cluster of differentiation 147 (CD147) contributes to breast cancer invasion, metastasis, and multidrug resistance. Recent studies have shown that peripheral soluble CD147 (sCD147) is increased in hepatocellular tumour and multiple myeloma patients and correlated with disease severity. This study aimed to assess the level, as well as the biological and clinical significance of sCD147 in breast cancer.
 
Methods: We tested plasma sCD147 levels in 308 breast cancer patients by enzyme-linked immunosorbent assay between February 2014 and February 2017. A subset of 165 cases of benign breast diseases was included as control group at the same period. We analysed the clinical significance of plasma sCD147 with relevance to clinicopathological factors of breast cancer patients.
 
Results: Plasma sCD147 levels were significantly higher in patients with primary breast cancer than those with benign breast diseases (P=0.001), in patients with locally advanced breast cancer (T3-T4 tumour) than those in early breast cancer (T1-T2 tumour; P=0.001), in patients with lymph node metastasis than in those without (P<0.001), and in patients with high recurrence risk than those with medium recurrence risk (P<0.001). Plasma sCD147 levels were also significantly higher in the chemotherapy-resistant group than in the chemotherapy-sensitive group (P=0.040). Plasma sCD147 was an independent predictor for lymph node metastasis in breast cancer patients (P=0.001).
 
Conclusion: This is the first study to demonstrate that plasma sCD147 levels are elevated in breast cancer patients. Soluble CD147 is also associated with tumour size, lymph node metastasis, high recurrent risk, and chemoresistance. Our findings support that plasma sCD147 is an independent predictive factor for lymph node metastasis.
 
 
New knowledge added by this study
  • Plasma sCD147 levels are elevated in breast cancer patients and are associated with tumour size, lymph node metastasis, high recurrent risk, and chemoresistance.
  • Plasma sCD147 is an independent predictive factor for lymph node metastasis.
Implications for clinical practice or policy
  • Plasma sCD147 may be used as the predictive factor to evaluate lymph node metastasis, recurrence risk, and chemoresistance of breast cancer.
  • Plasma sCD147 may contribute to the development of optimal adjuvant therapy for individual breast cancer patients.
 
 
Introduction
Breast cancer is the most common malignant tumour and the leading cause of cancer-related deaths among females in developing countries.1 Breast cancer displays heterogeneity: it comprises distinct pathologies and histological features and can have different chemotherapy responses and clinical outcomes.2 The identification of tumour-related factors that can predict tumour behaviour is important. Predictive factors can help identify as early as possible not only patients who have a high risk of recurrence and metastasis, but also patients who can benefit from different types of adjuvant therapy.3 Conventional predictive factors of high risk of recurrence and metastasis include relatively large (>5 cm) tumour size and high nuclear grade; negativity for oestrogen receptor and progesterone receptor; human epidermal growth factor receptor 2 (HER2) overexpression; and increased lymph node involvement at the time of breast cancer diagnosis.4 Recent advances in genetic profiling of tumours have extended our understanding of breast cancer biology and have allowed the use of several prognostic gene signatures to select patients at highest risk of early recurrence and those who may benefit from certain adjuvant treatment.2 5 6 However, despite receiving standard treatments routinely guided by predictive factors, more than 30% of breast cancer patients develop metastatic disease and have poor survival.7 8 As such, it is essential and urgent to identify reliable predictive factors to assist in diagnosis, staging, evaluation of recurrence risk, and development of new treatment modalities.
 
Cluster of differentiation 147 (CD147), a transmembrane glycoprotein that belongs to the immunoglobulin superfamily, can promote tumour invasion and metastasis, and mediate breast cancer drug resistance.9 10 11 12 13 Expression of CD147 is significantly correlated with axillary lymph node involvement; tumour, node, and metastasis staging; and shorter progression-free survival and overall survival.14 Previous data demonstrated that CD147 exists in both membrane-bound and soluble forms in many solid tumours, and soluble CD147 (sCD147) can be detected in the conditioned medium of tumour cells and peripheral blood of cancer patients.15 16 17 Overexpression of the CD147 gene in human breast cancer cells can increase the sCD147 level, indicating that sCD147 release is correlated with the degree of CD147 expression in tumour cells.15 16 17 Full-length CD147 may be exported into the microenvironment from tumour cells by microvesicle shedding or by matrix metalloproteinase (MMP)–dependent cleavage, thereby stimulating MMP expression in fibroblasts.18 19 20 In turn, sCD147 derived from tumour cells acts in a paracrine fashion on stromal cells that are both adjacent and distant to tumour sites, so as to further stimulate the production of MMPs and CD147. This additional CD147 consequently contributes to tumour angiogenesis, tumour growth, and metastasis.16 21 Importantly, several studies investigating the role of sCD147 level in patients with tumours have suggested that sCD147 may offer a useful approach in diagnosis, as it is correlated with disease severity.15 22 However, little is known about the level of sCD147 in patients with breast cancer. Furthermore, the biological and clinical significance of sCD147 in breast cancer has not been investigated.
 
In this study, we measured plasma sCD147 levels in patients with breast cancer and evaluated the results with respect to clinicopathological factors. We aimed to demonstrate the association between plasma sCD147 levels with tumour size, lymph node metastasis, recurrence risk, and chemoresistance in breast cancer patients.
 
Methods
Patients and samples
The results of this study are presented in accordance with the reporting recommendations for tumour marker prognostic studies.23 We conducted the study between February 2014 and February 2017 in the Affiliated Xiangya Hospital of Central South University in Changsha of Hunan Province, China. We collected peripheral blood samples from consecutive patients with breast cancer, including primary breast cancer, during their first hospital admission. To be eligible for this study, patients had to be adult females who had no other malignant diseases or severe systemic diseases, especially rheumatic, inflammatory, and cardiovascular diseases. The peripheral blood of consecutive patients with palpable benign breast masses, including fibroadenoma and adenopathy, was also collected to serve as control samples during the same period. All blood samples were centrifuged at 3000 rpm at 4°C for 5 minutes, and the plasma samples were stored at -70°C for later plasma sCD147 testing. All the patients’ clinicopathological findings were supplied by the Xiangya Hospital of Central South University. Breast cancer subtypes were identified according to the St Gallen Consensus 2013 classification system.24 Recurrence risk of breast cancer was evaluated according to the St Gallen Consensus 2007 criteria.25
 
The association between chemotherapy response and plasma sCD147 level was retrospectively analysed. The patients included in this analysis had to meet all of the following criteria: (1) had a confirmed diagnosis of invasive ductal breast carcinoma by pathology and had consented to undergo neoadjuvant chemotherapy; (2) had operable breast cancer consisting of a large tumour (>2 cm) that fulfilled the criteria for breast conserving surgery except tumour size, or triple-negative breast cancer (TNBC; ie, negative for oestrogen/progesterone receptors and HER2) with small (T1 stage) tumours; (3) had received no previous treatment; (4) had received only four cycles of pirarubicin-cyclophosphamide/epirubicin-cyclophosphamide (AC/EC)–based neoadjuvant chemotherapy before surgery; and (5) had complete hospital records that included evaluation of chemotherapy efficacy. Clinical response to AC/EC-based chemotherapy was evaluated by the decrease in tumour size and classified according to response evaluation criteria in solid tumours (RECIST criteria).26 Patients with complete remission or partial remission were classified as chemotherapy-sensitive, whereas patients with stable disease or progressive disease were classified as chemotherapy-resistant.
 
Enzyme-linked immunosorbent assay
The concentrations of plasma sCD147 were measured by enzyme-linked immunosorbent assay (ELISA). Plasma sCD147 levels were assessed using the EMMPRIN/CD147 ELISA kit (R&D Systems, Minneapolis [MN], US) according to the manufacturer’s protocol. The concentration of the sample in each ELISA well was determined by interpolation from a standard curve. Each sample was tested in duplicate.
 
Statistical analysis
The Mann-Whitney U test was used to compare levels of plasma sCD147 in different groups according to variable clinicopathological factors. The Chi squared contingency test with Yates correction was used to determine the relationship between clinicopathological factors of breast cancer patients and lymph node status or chemotherapy sensitivity. Binary logistic regression was used to assess clinicopathological factors (plasma sCD147, tumour size, and HER2) that were associated with lymph node metastasis or chemoresistance in invasive breast cancer. All multivariable logistic regression models used backward stepwise procedures, and only datasets complete for every outcome analysed were used. Receiver operating characteristic (ROC) curve analysis was performed to calculate the area under the curve and evaluate the optimal cut-off point, which was given by the maximum of the Youden index. Statistical significance was set at P<0.05. The GraphPad Prism 6 software (GraphPad Software, La Jolla [CA], US) and SPSS (Windows version 19.0; IBM Corp, Armonk [NY], US) were used for statistical analysis.
 
Results
Patient’ characteristics
Among all eligible patients with complete records, 165 had benign breast disease (age range, 22-68 years) and 308 had primary breast cancer (age range, 24-77 years). There was no significant difference in age between the two groups (P=0.381). Breast cancer patients comprised 11 with ductal carcinoma in situ and 297 with invasive ductal carcinoma. Retrospective analysis of the association of plasma sCD147 level with response to neoadjuvant chemotherapy included 175 patients who met all the inclusion criteria (Fig)—luminal A in 39, luminal B in 70, HER2-positive in 28, and TNBC in 38. In all, 170 patients had T2-T4 tumours and five had T1 TNBC tumours. Using the RECIST criteria, we assigned the 175 patients to two groups: chemotherapy-sensitive (n=126) and chemotherapy-resistant (n=49).
 

Figure. Patient flowchart
 
Plasma soluble CD147 levels in breast cancer patients
According to ELISA results, plasma sCD147 levels were significantly higher in patients with primary breast cancer than in those with benign breast disease (median [interquartile range; IQR], 8629.81 pg/mL [7426.33-10 309.20 pg/mL] vs 7625.99 pg/mL [6739.20-9140.04 pg/mL]; P=0.001). However, there was no significant difference in plasma sCD147 levels between patients with invasive breast cancer and those with ductal carcinoma in situ (8618.91 pg/mL [7404.81-10 358.50 pg/mL] vs 9185.79 pg/mL [7671.15-9626.47 pg/mL]; P=0.787). Regarding cancer subtypes of the 297 patients with invasive breast carcinoma, median (IQR) plasma sCD147 levels were significantly higher in patients with HER2-positive breast cancer (10 042.34 pg/mL [7772.01-11 058.48 pg/mL]) than in those with luminal A tumours (7991.05 pg/mL [7101.72-10 237.4 pg/mL]; P=0.007), luminal B tumours (8629.81 pg/mL [7200.45-9953.32 pg/mL]; P=0.017), and TNBC tumours (8585.16 pg/mL [7884.27-10 545.51 pg/mL]; P=0.027).
 
Association between plasma soluble CD147 and clinicopathological factors
The association between plasma sCD147 level and clinicopathological factors in patients with invasive breast cancer is summarised in Table 1. Plasma sCD147 levels increased with tumour size: median (IQR) levels were significantly higher in patients with locally advanced (stage T3-T4) than those with early (stage T1-T2) breast cancer (10 093.26 pg/mL [7974.73-11 451.21 pg/mL] vs 8561.45 pg/mL [7169.41-9952.90 pg/mL]; P=0.001). Plasma sCD147 levels were also elevated in patients with lymph node metastasis compared with those without (median [IQR], 9991.42 pg/mL [8154.61-11 452.84 pg/mL] vs 7814.78 pg/mL [6936.82-9516.85 pg/mL]; P<0.001). In addition, plasma sCD147 levels were significantly higher in patients with a high risk of recurrence than in those with a medium risk (median [IQR], 10 093.26 pg/mL [8135.35-11 679.71 pg/mL] vs 8134.68 pg/mL [7151.41-9616.68 pg/mL]; P<0.001). Although plasma sCD147 levels were elevated for the HER2- positive breast cancer subtype as compared with other breast cancer subtypes, there was no significant difference between HER2-positive and HER2-negative patients (median [IQR], 9254.34 pg/mL [7157.63-11 199.38 pg/mL] vs 8568.83 pg/mL [7448.34-10 070.42 pg/mL]; P=0.160).
 

Table 1. Association between plasma soluble CD147 and various clinicopathological factors (n=297)
 
Plasma soluble CD147 as an independent predictor for lymph node metastasis
Because plasma sCD147 was associated with lymph node status and recurrent risk, we speculated that plasma sCD147 may be a predictor for lymph node metastasis of breast cancer. Univariate analysis showed that tumour size and HER2 status may be involved in lymph node metastasis (Table 2). We subsequently used binary logistic regression analysis to identify clinicopathological factors associated with lymph node metastasis in invasive breast cancer. Our data showed that plasma sCD147 (P<0.001), HER2-positive tumours (P=0.001), and tumour size T3-T4 (P=0.005) were independent predictors of lymph node metastasis of breast cancer (Table 3). When we analysed ROC curves to evaluate use of plasma sCD147 as a diagnostic biomarker for lymph node metastasis, the area under the curve was 0.745 (95% confidence interval, 0.676-0.813) and the optimal cut-off point of plasma sCD147 was 8577 pg/mL, which provided a sensitivity of 70.9% and a specificity of 61.7%.
 

Table 2. Association between clinicopathological factors and lymph node involvement (n=297)
 

Table 3. Results of multivariable analysis of clinicopathological factors and lymph node metastasis
 
Association of plasma soluble CD147 levels with chemotherapy response
Table 1 shows that plasma sCD147 levels in the chemotherapy-resistant group were significantly higher than those in the chemotherapy-sensitive group (median [IQR], 10 093.26 pg/mL [7974.73-11 261.88 pg/mL] vs 8585.16 pg/mL [7789.74-9868.87 pg/mL]; P=0.040). Univariate analysis revealed that tumour size and HER2 status may be involved in chemotherapy response (Table 4). Binary logistic regression analysis demonstrated that plasma sCD147 was not an independent predictor for chemotherapy response of breast cancer patients, but tumour size of T3-T4 was (P=0.001) [Table 5].
 

Table 4. Association between tumour characteristics and chemotherapy response (n=175)
 

Table 5. Results of multivariable analysis of clinicopathological factors and chemotherapy resistance
 
Discussion
The tumour microenvironment plays a proactive role in malignant disease progression, including the transition from ductal carcinoma in situ to invasive cancer, tumour cell proliferation, dissemination, and metastasis.27 CD147 has been found to be overexpressed in breast cancer, associated with tumour size and staging, and predictive of poor prognosis.28 29 30 31 Tumour cells express molecules, either secreted or presented on the cell surface, that interact with surrounding stromal cells. Soluble CD147 may be released from membrane-associated CD147 as a result of both MMP proteolytic activity and microvesicle shedding in the tumour microenvironment. Soluble CD147 may then act in a paracrine fashion on stromal cells to further trigger production of MMPs and CD147; the latter contributes to tumour angiogenesis, tumour growth, and metastasis.16 19 21
 
Wu et al15 reported that serum sCD147 enhances the secretion of MMP-2 from hepatocellular carcinoma cells by activating extracellular signal-regulated kinase and focal adhesion kinase, as well as phosphoinositide-3-kinase/Akt signalling, indicating that sCD147 may contribute to hepatocellular carcinoma progression. Moreover, serum sCD147 was elevated in patients with hepatocellular carcinoma compared with healthy individuals, and sCD147 level was associated with tumour size and Child-Pugh score.15 Gross et al22 also reported that sCD147 levels were elevated in patients with multiple myeloma, and elevated levels were associated with refractory disease and shortened progression-free survival, indicating that sCD147 may be a new prognostic factor for patients with multiple myeloma.
 
A previous study demonstrated that CD147 was overexpressed in human breast cancer.10 In this study, we measured plasma sCD147 levels by ELISA and found that plasma sCD147 levels were significantly elevated in breast cancer patients compared with control patients who had benign breast diseases. We also found that plasma sCD147 was significantly elevated in lymph node metastasis in breast cancer patients. Taken together, these data show that plasma sCD147 may be released from tumour cells and promote lymph node metastasis of breast cancer. Some studies have reported that sCD147 has been detected in patients with inflammatory diseases31 or cardiovascular diseases.32 33 To eliminate interference from other diseases and conditions, we excluded patients with inflammatory or cardiovascular diseases and ensured patients in each group had a similar age distribution.
 
Previous studies have shown that membrane-bound CD147 may correlate with HER2 expression. Yan et al34 reported that CD147 induces angiogenesis by stimulating vascular endothelial growth factor production, invasiveness by stimulating MMP production, and multidrug resistance by hyaluronan-mediated upregulation of HER2 signalling. Xue et al30 reported that CD147 expression was positively correlated with HER2 overexpression. In a recent study, CD147 knockdown was shown to improve the antitumour efficacy of trastuzumab in HER2-positive breast cancer cells.35 Although we found that plasma sCD147 levels were significantly higher in the HER2-positive breast cancer subtype than in luminal A, luminal B, and TNBC subtypes, plasma sCD147 had no association with expression of HER2 or oestrogen/progesterone receptors in breast cancer. The reason for this finding is that there are four breast cancer subtypes—luminal A, luminal B, HER2-positive, and TNBC—according to oestrogen/progesterone receptor, HER2, and Ki67 status. The luminal B subtype includes some breast cancers that are positive for oestrogen/progesterone receptor and HER2. Hence, patients who are HER2-positive (Table 1) include those with HER2-positive subtype and also luminal B subtype; plasma sCD147 levels in patients who were ‘HER2-positive’ were different from those with a HER2-positive subtype.
 
It is essential to establish predictive factors to allow evaluation of the recurrence risk of breast cancer, so that optimal adjuvant therapy can be selected for individual patients.3 36 Larger tumour size at diagnosis, high proliferation factors, absence of oestrogen/progesterone receptors and HER2 overexpression, and lymph node metastasis are related to a high risk of recurrence and poor survival, and are commonly recognised as prognostic and predictive factors for breast cancer recurrence risk.4 37 38 Consistent with these findings, we found that plasma sCD147 levels were significantly increased in patients with locally advanced lymph node metastasis and a high risk of breast cancer recurrence. We also found that plasma sCD147 was positively associated with tumour size, lymph node metastasis, and high recurrence risk of invasive breast cancer.
 
Lymph node status, which confers different strategies for patients at different tumour stages, is critical information for the treatment of breast cancer, and the accurate prediction of lymph node status is a prerequisite for treatment decision. Our binary logistic regression analysis showed that plasma sCD147, HER2 positive subtype, and tumour size (T3-T4) were independent predictors for lymph node metastasis of breast cancer patients. Taken together, these data suggest that plasma sCD147 may be a new factor for the evaluation of breast cancer recurrence risk. Our ROC analysis demonstrated that plasma sCD147 could be a biomarker for distinguishing breast cancer patients with lymph node metastasis from those without; however, the sensitivity and specificity were not high (70.9% and 61.7%, respectively). The relatively low sensitivity and specificity suggest that using plasma sCD147 as the sole biomarker may result in substantial numbers of false positives and false negatives. Therefore, it may be necessary to investigate whether the combination of plasma sCD147 and other biomarkers can improve efficacy.
 
According to the data of 303 patients who were followed up for 3 to 38 months (median, 20 months), 11 patients had relapse: two had local recurrences and nine had distant metastases. The mean time of recurrence/metastasis was 23.6 months, with no difference between patients with relapse and those without (Table 6). We were not able to investigate the relationship between plasma sCD147 and disease-free survival or overall survival, because of the short median follow-up period.
 

Table 6. Follow-up data on relapse status
 
Previous data have shown that CD147 is one of the apoptosis-related proteins and it may mediate adriamycin chemoresistance in breast cancer by affecting the cellular localisation and dimerisation of the protein ABCG2 (ATP-binding cassette subfamily G member 2).10 In this study, we studied the relationship between plasma sCD147 and chemotherapy response in invasive breast cancer. All patients were given four cycles of AC/EC-based chemotherapy. We also found that plasma sCD147 levels were significantly higher in the chemotherapy-resistant group than in the chemotherapy-sensitive group, and such levels were positively associated with chemotherapy resistance. Although our data also showed that plasma sCD147, tumour size (T3-T4), and HER2 positive subtype may be involved in chemotherapy response, binary logistic regression demonstrated that tumour size (T3-T4) was an independent predictor for chemotherapy response of breast cancer patients, but plasma sCD147 was not. Owing to the small number of cases in the chemotherapy-resistant group, the statistical analysis of data may be underpowered.
 
In addition to the small sample of study and short median follow-up period, there were other limitations in this study. This study was conducted in one centre, and the researchers who extracted the data and conducted the analysis were not blinded to the study hypothesis. There may have increased selection and information bias. Furthermore, as the design of this study was relatively simple, there may be insufficient control for potential confounding factors in the multivariable analysis.
 
In conclusion, our study found that plasma sCD147 levels were elevated in breast cancer patients compared with controls with benign breast disease, and plasma sCD147 level was associated with tumour size, lymph node metastasis, high recurrence risk, and AC/EC-based chemoresistance. Moreover, our study supports that plasma sCD147 is an independent predictive factor for lymph node metastasis and is a feasible marker to distinguish breast cancer patients with lymph node metastasis from patients without.
 
Author contributions
Concept or design: LL Tang, LQ Liao.
Acquisition of data: YJ Liu, YH Kuang, SM Wang, GJ Yan.
Analysis or interpretation of data: LL Tang, LQ Liao.
Drafting of the article: YH Kuang, LQ Liao.
Critical revision for important intellectual content: YH Kuang, LQ Liao.
YH Kuang, YJ Liu, and LL Tang contributed equally to this study.
 
Funding/support
This study was supported by two grants from the National Natural Science Foundation of China (No. 81101654, awarded to LQ Liao, and No. 81573049, awarded to YH Kuang).
 
Declaration
The authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
The research protocols for the use of human tissue were approved by and conducted in accordance with the policies of the Institutional Review Boards at Central South University (Ref No. 201403152), which were formulated based on the 1964 Helsinki Declaration and its later amendments. Written informed consent was obtained from all participants.
 
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Outcomes of salvage radiotherapy for recurrent prostate cancer after radical prostatectomy

Hong Kong Med J 2018 Jun;24(3):218–25 | Epub 21 May 2018
DOI: 10.12809/hkmj176888
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Outcomes of salvage radiotherapy for recurrent prostate cancer after radical prostatectomy
Eric KC Lee, MB, ChB, FHKAM (Radiology); WH Mui, MB, BS, FHKAM (Radiology); Adrian W Chan, MB, BS, FRCR; Y Tung, MB, BS, FHKAM (Radiology); Frank CS Wong, MB, ChB, FHKAM (Radiology)
Department of Clinical Oncology, Tuen Mun Hospital, Tuen Mun, Hong Kong
 
Corresponding author: Dr Eric KC Lee (leekachai2000@yahoo.com.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Salvage radiotherapy (SRT) provides effective biochemical control for patients with prostate cancer who have prostate-specific antigen (PSA) failure after radical prostatectomy. However, the effect of SRT on long-term clinical outcomes remains unknown. Therefore, we report the natural history of patients treated with SRT.
 
Methods: We identified 84 Chinese patients with prostate cancer treated with SRT to the prostatic fossa alone during 2006-2017 at Tuen Mun Hospital, Hong Kong. Survival was calculated using Kaplan-Meier method. Log rank test and Cox regression were used to determine significance of clinical parameters with outcomes.
 
Results: Median SRT dose given was 70 Gy (range, 64-76 Gy). Median pre-SRT PSA level was 0.4 ng/mL (0.2-7.4 ng/mL). After SRT, 47 (56%) patients had undetectable (<0.1 ng/mL) PSA levels. After median follow-up of 48 months (2 months to 10 years), 25 (30%) patients had further biochemical progression. Subsequently, 12 patients received androgen deprivation therapy and nine (11%) developed distant metastasis. The 5-year biochemical progression–free survival, androgen deprivation therapy–free survival and metastasis-free survival were 62.7%, 83.5% and 86.7%, respectively. Early PSA failure after radical prostatectomy (hazard ratio=7.4), negative surgical margin (hazard ratio=2.7), positive extracapsular extension (hazard ratio=4.6), and detectable PSA levels after SRT (hazard ratio=17.3) were associated with lower biochemical progression–free survival after SRT.
 
Conclusions: High-dose SRT with intensity-modulated radiotherapy/volumetric modulated arc radiotherapy is an effective local treatment that can prevent distant metastasis and avoid the need for androgen deprivation therapy in Chinese patients who have PSA failure after radical prostatectomy.
 
 
New knowledge added by this study
  • Better biochemical progression–free survival after salvage radiotherapy (SRT) can be achieved through higher radiation doses and better selection of patients.
  • Patients with prostate-specific antigen (PSA) failure ≤24 months after radical prostatectomy, negative surgical margin, positive extracapsular extension, or detectable PSA after SRT are more likely to develop biochemical progression after SRT.
Implications for clinical practice or policy
  • Distant metastasis is more likely to occur in patients with extracapsular extension, patients who cannot achieve biochemical complete response, and patients who develop biochemical progression within 1 year of SRT.
  • For these patients, close monitoring for distant metastasis may be needed.
 
 
Introduction
Prostate cancer (PCa) is the most common non-cutaneous malignancy among men in western countries, and is the third most common cancer among men in Hong Kong.1 Increasing public awareness in the Chinese community, as well as the common use of prostate-specific antigen (PSA) tests by primary health physicians, have led to detection of PCa at an earlier stage, when it is amenable to either radical surgery or radiotherapy (RT).2 Because of recent advancements in operative management, such as robotic-assisted laparoscopic prostatectomy,3 many patients have found radical prostatectomy (RP) the preferred treatment option. Nevertheless, adjuvant radiotherapy (ART) to the prostatic fossa is indicated postoperatively in cases with positive surgical margin (SM), or residual disease from extracapsular extension (ECE). Alternatively, patients may receive salvage radiotherapy (SRT) when there is PSA failure, defined as any detectable and rising PSA level after RP.
 
Currently, ART is still being compared with SRT in three randomised controlled trials (RADICALS, RAVES, GETUG-AFU 17).4 5 6 While the results of these European and Australasian studies are still pending, the American Society for Radiation Oncology/American Urological Association guidelines recommend that physicians offer SRT to patients with PSA or local recurrence after RP in whom there is no evidence of distant metastasis (DM).7 Patients should be advised that SRT should be administered at the earliest sign of PSA recurrence. Approximately 60% of patients who are treated with SRT before the PSA level rises to >0.5 ng/mL will achieve an undetectable PSA level, providing long-term PSA control in nearly half of them.8
 
However, after SRT, some patients may still experience further clinical progression, including DM and cancer-related death. The effect of SRT on the long-term outcomes including metastasis-free survival (MFS) and overall survival—especially in Chinese patients—is not well understood. Herein we report the long-term survival data of patients at a single institution in Hong Kong who received SRT to the prostatic fossa using modern RT techniques.
 
Methods
Patient selection
Using the MOSAIQ system (version 2.62, IMPAC Medical Systems, Inc.; Sunnyvale [CA], US), we identified 91 Chinese patients treated with postoperative RT to the prostatic fossa at Tuen Mun Hospital, Hong Kong, between 2006 and 2017. The treatment records and clinical data of these patients were reviewed. Two patients who received ART with undetectable PSA were excluded. Patients who had received androgen deprivation therapy (ADT) prior to SRT were also excluded. These selection criteria yielded 84 evaluable individuals who received SRT to the prostatic fossa alone for PSA failure (defined as detection of PSA concentration at 0.2 ng/mL, with a second confirmatory level detected at 0.2 ng/mL) more than 3 months after RP.
 
Radiation therapy techniques
A planning computed tomographic scan was performed for each patient with 3-mm slice thickness, and the clinical target volume was determined with reference to one of the published consensus guidelines.9 10 11 The usual boundaries of the clinical target volume are: inferiorly, 5 mm below the urethral anastomosis; anteriorly, the posterior aspect of the symphysis pubis or the posterior third of the bladder; laterally, the medial border of the obturator internus and levator ani muscles; posteriorly, the anterior mesorectal fascia; and superiorly, 5 mm above the surgical bed. The planning target volume was defined as clinical target volume with a margin of 4 to 5 mm posteriorly and 0.7 to 1 cm in all other directions. Organs at risk, including the rectum, bladder, and bilateral femoral heads were contoured. Conformal radiotherapy or inverse planning techniques with intensity-modulated radiotherapy (IMRT) using seven to nine static beams were used before October 2010. After that, volumetric modulated arc radiotherapy (VMAT) was employed using the Pinnacle treatment planning system (Philips Medical Systems, Fitchburg [WI], US) with treatment delivered through one to two dynamic cone arcs.
 
Variable definition
Clinical data included age at SRT, time from surgery to RT (≤24 months vs >24 months), SRT dose, pre-SRT PSA level, and post-SRT nadir PSA. Pathological data consisted of pathological T stages (T2a vs T2b vs T2c vs T3a or T3b), ECE, seminal vesicle invasion, SM, and pathological Gleason scores (≤7 or ≥8).
 
Outcome definition
After SRT, patients were followed up with PSA level checks every 3 months in the first 2 years, every 6 months from year 3 to year 5, then annually. A complete response was defined as an undetectable nadir PSA (<0.1 ng/mL). Biochemical progression (PSA failure) was defined as a rise of PSA level by 0.2 ng/mL above the nadir with a second confirmation at least 1 week apart.12 Biochemical progression-free survival (bPFS) was defined as the date from SRT completion to the first date of biochemical progression. Patients who showed biochemical progression or symptoms suggestive of metastasis received imaging studies at the discretion of the oncologist. Metastasis-free survival was defined as the date from SRT completion to the date of occurrence of metastasis on imaging. Patients who showed biochemical progression with or without metastasis were counselled on the use of ADT; ADT-free survival was defined as the date of SRT completion to the first date of ADT administration.
 
Statistical analyses
The Kaplan-Meier method was used to estimate bPFS, MFS, and ADT-free survival. Log-rank tests and Cox regression analysis were used to test the association between groups and oncologic outcomes. Covariates consisted of continuous variables, including patient age at SRT, SRT dose, and pre-SRT PSA, and discrete variables including post-SRT nadir PSA (detectable vs undetectable), pathological T stages (T2a vs T2b vs T2c vs T3a vs T3b), pathological Gleason score (≤7 vs ≥8), SM (negative vs positive), ECE (negative vs positive), seminal vesicle invasion (negative vs positive), and time of SRT (≤24 months after RP or >24 months after RP). Only variables that were significantly associated with outcomes on univariate analyses were further tested for association in multivariate analyses.
 
Statistical analyses were performed using IBM SPSS Statistics for Windows, version 24.0 (IBM Corp, Armonk [NY], US), and numerical data were presented according to Cole.13
 
Results
Patients
The median age of the 84 patients was 68 years (range, 52-79 years) when they received SRT. The patients’ median pre-SRT PSA level was 0.4 ng/mL (range, 0.2-7.4 ng/mL). Of the patients, 63 (75%) had positive SM in their prostatectomy specimens. Extracapsular extension was detected in 25 (29.8%) patients. Pelvic lymph nodes of 41 patients were sampled during RP and were all found to be negative for malignancy. These and other pathological characteristics are summarised in Table 1. The median time from surgery to start of SRT was 18.4 months (range, 3.8-121 months).
 

Table 1. Patient and RP pathological characteristics (n=84)
 
Treatment delivery
Before October 2010, one patient was treated with conformal RT and 10 patients were treated with IMRT. Subsequently the other 73 patients were treated with VMAT. The median dose given to the prostatic fossa was 70 Gy (range, 64-76 Gy), with 66 (79%) patients receiving a dose of ≥70 Gy. The mean dose delivered using VMAT (69.5 Gy) was slightly higher than that delivered using IMRT/conformal RT (68.1 Gy) [independent-samples t test, t=2.1; P=0.028].
 
Treatment outcome
Of 84 patients, 47 (56%) had undetectable PSA levels (complete response; <0.1 ng/mL) after SRT. After a median follow-up of 48 months (range, 2-120 months), 25 (30%) patients had biochemical progression with an estimated 5-year bPFS of 62.7% (95% confidence interval [CI], 50.1-75.3%) [Fig 1a]. Among the 25 patients who developed biochemical progression after SRT, seven were found to have DM and subsequently received ADT, and five started ADT in the absence of DM, two of whom later developed DM and had their disease became castration-resistant. Overall, 12 patients received ADT and nine (11%) patients developed DM. The 5-year ADT-free survival and MFS were 83.5% (95% CI, 73.7-93.3%) and 86.7% (95% CI, 77.7-95.7%), respectively (Fig 1b, c). Notably, only six patients died, all from causes other than PCa.
 

Figure 1. (a) Biochemical progression–free survival, (b) androgen deprivation therapy–free survival, and (c) metastasis-free survival of patients after salvage radiotherapy
 
Biochemical progression–free survival and metastasis-free survival
On univariate analysis, a post-SRT nadir PSA ≥0.1 ng/mL, positive ECE, and bPFS ≤12 months were significantly associated with a shorter MFS (all P<0.001; Fig 2). Similarly, a post-SRT nadir PSA ≥0.1 ng/mL (P<0.001), positive ECE (P<0.001), negative SM (P=0.045), pathological Gleason score ≥8 (P=0.002), and time from surgery to SRT ≤24 months (P=0.008) were significant predictors of a shorter bPFS (Fig 3). The pre-SRT PSA level, age, and SRT dose were not associated with either MFS or bPFS in this cohort on univariate analysis. On multivariate analysis using the Cox regression method, negative SM (hazard ratio [HR]=2.7; 95% confidence interval [CI], 1.1-6.6), positive ECE (HR=4.6; 95% CI, 1.8-11.7), post-SRT nadir PSA ≥0.1 ng/mL (HR=17.3; 95% CI, 5.3-57.0), and time from surgery to SRT ≤24 months (HR=7.4; 95% CI, 2.2-24.0) retained significant association with a shorter bPFS (Table 2). There was no variable significantly associated with MFS after multivariate analysis.
 

Figure 2. Metastasis-free survival by (a) nadir PSA; (b) bPFS; and (c) ECE (all P<0.001)
 

Figure 3. Biochemical progression–free survival by (a) nadir PSA; (b) GS; (c) SM; (d) ECE; and (e) time from RP to SRT
 

Table 2. Predictive factors of shorter bPFS on multivariate analysis
 
Discussion
Most patients who develop biochemical recurrence after RP for localised PCa remain asymptomatic for many years.14 However, patients with increasing PSA level are at high risk of developing DM. Salvage radiotherapy is effective in terms of biochemical control when it is administered at low PSA level. Stephenson et al12 reported a 6-year progression-free probability of 32% after SRT. In their multi-institutional retrospective cohort of 1603 consecutive patients from 17 North American tertiary referral centres who received SRT after RP for PSA recurrence between 1987 and 2005, the median dose was only 64.8 Gy (interquartile range, 63-66 Gy) delivered using older techniques. The 5-year bPFS of 62.7% in the present study is similar or better than those reported in western countries.12 15 16 This might be due to better selection of patients (most patients started SRT when their PSA level was ≤0.5 ng/mL), or the higher dose of SRT to the prostatic fossa (median 70 Gy). In our cohort, all patients but one were treated using IMRT/VMAT. Intensity-modulated radiotherapy was introduced in the 1990s and it has since enabled radiation oncologists to deliver higher doses of radiation to treat patients with PCa—including patients with residual disease at the prostatic fossa—without causing excessive radiation damage to healthy tissue.17 18 19 Volumetric modulated arc radiotherapy has recently attracted much interest because it can dynamically deliver a radiation dose during rotation of the gantry; this is also superior to IMRT in terms of its plan qualities and efficiency in the treatment of PCa.20 21
 
Pisansky et al22 reported that SRT doses of ≥66.0 Gy were associated with reduced cumulative incidence of biochemical progression. A systemic review by King23 provides level 2a evidence for escalated SRT dose of at least 70 Gy. A 2% improvement in relapse-free survival can be achieved for each additional Gy from 60 Gy to 70 Gy.23 However, higher SRT dose was not shown to be associated with better bPFS/MFS in our 84 patients by univariate analysis, because most (79%) had been treated with an SRT dose of ≥70 Gy, and the follow-up time may still be too short to demonstrate any further dose-response relationship. We postulated that such high-dose SRT can be delivered safely with modern techniques using VMAT, therefore our current usual prescribed dose is 70 Gy to the prostatic fossa, unless limited by dose constraints of the organ at risk. We have previously shown the efficiency and low toxicities using VMAT for SRT to the prostatic fossa.24 Longer follow-up is necessary to ensure that late complications are within safety limits.
 
Despite the success of SRT in biochemical control, some patients may develop further biochemical progression. In our present study, patients whose surgical pathology revealed negative margin and positive ECE had a shorter bPFS (HRs of 2.7 and 4.6, respectively). Patients who start SRT within 2 years of RP may also have a shorter PSA doubling time, leading to earlier detection of recurrence. These patients have a greater than 7-fold higher risk of biochemical regression after SRT than those with later recurrence. Salvage radiotherapy to the prostatic fossa alone cannot eradicate cancer that has spread outside the surgical bed after RP. In fact, negative SM, positive ECE, and shorter PSA doubling time are three of the many adverse factors which predict a shorter bPFS after SRT, using the nomogram proposed by Stephenson et al.25 However, we cannot demonstrate the importance of pre-SRT PSA level in our patient cohort because more than 65% of the patients had started SRT when their PSA level was ≤0.5 ng/mL.
 
Overall, the role of SRT in improving MFS and overall survival is less certain, because the disease can be indolent and mortality due to causes other than PCa is more likely in older patients. Patients also have other complications related to disease progression, such as painful bone metastasis. Efforts have been made to identify surrogate endpoints that can predict further disease progression, metastasis, and even cancer-related death after SRT. In a single institution review, Johnson et al26 reported approximately 50% of men experience further biochemical progression after SRT. Those who have a short interval to biochemical progression of ≤18 months after SRT are most likely to experience DM, PCa-specific mortality, and overall mortality. Bartkowiak et al27 reported on the long-term outcomes of patients with a median follow-up of 7 years (maximum, 14 years) after SRT. They found that a post-SRT nadir PSA <0.1 ng/mL was associated with improved bPFS and overall survival. The results of our univariate analysis support the abovementioned findings27 (Fig 2a, b). On multivariate analysis, we found that undetectable nadir PSA (<0.1 ng/mL) is the most important factor for predicting longer bPFS (Table 2). In the present study, of the 47 patients who achieved biochemical complete response after SRT, none developed DM. In contrast, among the 25 patients who had biochemical progression, nine whose disease progressed within 1 year after SRT eventually developed DM. Although our result of a 5-year MFS of nearly 90% is encouraging, with the median follow-up of only 4 years, we can hypothesise only that better biochemical control is correlated with improvements in other clinical outcomes. For patients whose PSA level does not become undetectable and rapidly rises within 1 year after SRT (bPFS ≤12 months), close monitoring for DM may be needed.
 
The improvement in overall survival and MFS of adjuvant ADT with SRT has been demonstrated by Shipley et al28 in a phase III study. However, ADT is not routinely recommended to our patients because of the known metabolic and cardiovascular toxicities and the negative impact on patients’ quality of life. In addition, most of our patients have fewer adverse features than those reported by Shipley et al.28 For patients with biochemical regression alone after SRT, we suggest monitoring for any site of disease recurrence such that further SRT could still be feasible. Nonetheless, we applied positron emission tomography with 68 Ga-labelled prostate-specific membrane antigen (PET-PSMA) to identify the site of recurrence in four of our patients when their PSA levels increased to ≥2.2 ng/mL (Table 3). All four patients were found to have DM which was not amenable to further local treatment and ADT had become their only option. It remains unclear whether PET-PSMA or other imaging studies at lower PSA levels are sensitive or useful enough to alter the management decision.29 Further research to study the use of novel radiological examinations in this situation is needed.
 

Table 3. Pattern of disease progression
 
Conclusions
This is the first report to demonstrate the therapeutic effects in terms of bPFS and MFS of SRT in Chinese patients in a Hong Kong centre. Salvage radiotherapy is an effective local treatment that can prevent DM and avoid the need for ADT in most patients who have PSA failure after RP in Chinese patients. Our results appear to be better than those of some studies in western countries, in which older radiotherapy techniques and lower radiation doses were used. The limitations of our study include the retrospective design with lack of evaluation of patients’ reported outcome, small sample size, and short duration of follow-up. A multi-institutional study is recommended to collect more local data and experiences.
 
Author contributions
Concept or design: EKC Lee, Y Tung.
Acquisition of data: EKC Lee, AW Chan.
Analysis or interpretation of data: EKC Lee.
Drafting of the article: EKC Lee, WH Mui, FCS Wong.
Critical revision for important intellectual content: EKC Lee, WH Mui, FCS Wong.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity. An earlier version of this paper was presented as poster presentation at the 9th European Multidisciplinary Meeting on Urological Cancers, 16-19 November 2017, Barcelona, Spain.
 
Ethical approval
The study was conducted with approval from the New Territories West Cluster Clinical and Research Ethics Committee.
 
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3. Ng AT, Tam PC. Current status of robot-assisted surgery. Hong Kong Med J 2014;20:241-50. Crossref
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6. Trans Tasman Radiation Oncology Group. RAVES trial: radiotherapy—adjuvant versus early salvage. Available from: http://www.clinicaltrial.gov/ct2/show/NCT00860652. Accessed Jul 2017.
7. Valicenti RK, Thompson I Jr, Albertsen P, et al. Adjuvant and salvage radiation therapy after prostatectomy: American Society for Radiation Oncology/American Urological Association guidelines. Int J Radiat Oncol Biol Phys 2013;86:822-8. Crossref
8. Wiegel T, Lohm G, Bottke D, et al. Achieving an undetectable PSA after radiotherapy for biochemical progression after radical prostatectomy is an independent predictor of biochemical outcome—results of a retrospective study. Int J Radiat Oncol Biol Phys 2009;73:1009-16. Crossref
9. Michalski JM, Lawton C, El Naqa I, et al. Development of RTOG consensus guidelines for the definition of the clinical target volume for postoperative conformal radiation therapy for prostate cancer. Int J Radiat Oncol Biol Phys 2010;76:361-8. Crossref
10. Poortmans P, Bossi A, Vandeputte K, et al. Guidelines for target volume definition in post-operative radiotherapy for prostate cancer, on behalf of the EORTC Radiation Oncology Group. Radiother Oncol 2007;84:121-7. Crossref
11. Sidhom MA, Kneebone AB, Lehman M, et al. Post-prostatectomy radiation therapy: consensus guidelines of the Australian and New Zealand Radiation Oncology Genito-Urinary Group. Radiother Oncol 2008;88:10-9. Crossref
12. Stephenson AJ, Scardion PT, Kattan MW, et al. Predicting the outcome of salvage radiation therapy for recurrent prostate cancer after radical prostatectomy. J Clin Oncol 2007;25:2035-41. Crossref
13. Cole TJ. Too many digits: the presentation of numerical data. Arch Dis Child 2015;100:608-9. Crossref
14. Pound CR, Partin AW, Eisenberger MA, Chan DW, Pearson JD, Walsh PC. Natural history of progression after PSA elevation following radical prostatectomy. JAMA 1999;281:1591-7. Crossref
15. Geinitz H, Riegel MG, Thamm R, et al. Outcome after conformal salvage radiotherapy in patients with rising prostate-specific antigen levels after radical prostatectomy. Int J Radiat Biol Oncol Phys 2012;82:1930-7. Crossref
16. Fossati N, Karnes RJ, Boorjian SA, et al. Long-term impact of adjuvant versus early salvage radiation therapy in pT3N0 prostate cancer patients treated with radical prostatectomy: results from a multi-institutional series. Eur Urol 2017;71:886-93. Crossref
17. Goldin GH, Sheets NC, Meyer A, et al. Patterns of intensity modulated radiation therapy (IMRT) use for the definitive and postoperative treatments of prostate cancer: a SEER-medicare analysis. Int J Radiat Oncol Biol Phys 2011;81(2 Suppl):S408. Crossref
18. Nath SK, Sandhu AP, Rose BS, et al. Toxicity analysis of postoperative image-guided intensity-modulated radiotherapy for prostate cancer. Int J Radiat Oncol Biol Phys 2010;78:435-41. Crossref
19. Ost P, De Troyer B, Fonteyne V, Oosterlinck W, De Meerleer G. A matched control analysis of adjuvant and salvage high-dose postoperative intensity-modulated radiotherapy for prostate cancer. Int J Radiat Oncol Biol Phys 2011;80:1316-22. Crossref
20. Kopp RW, Duff M, Catalfamo F, Shah D, Rajecki M, Ahmad K. VMAT vs. 7-field-IMRT: assessing the dosimetric parameters of prostate cancer treatment with a 292-patient sample. Med Dosim 2011;36:365-72. Crossref
21. Palma D, Vollans E, James K, et al. Volumetric modulated arc therapy for delivery of prostate radiotherapy: reduction in treatment time and monitor unit requirements compared to intensity modulated radiotherapy. Int J Radiat Oncol Biol Phys 2008;72(1 Suppl):S312. Crossref
22. Pisansky TM, Agrawal S, Hamstra DA, et al. Salvage radiation therapy dose response for biochemical failure of prostate cancer after prostatectomy—A multi-institutional observational study. Int J Radiat Oncol Biol Phys 2016;96:1046-53. Crossref
23. King CR. The dose-response of salvage radiotherapy following radical prostatectomy: a systemic review and meta-analysis. Radiother Oncol 2016;121:199-203. Crossref
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Hypospadias surgery in children: improved service model of enhanced recovery pathway and dedicated surgical team

Hong Kong Med J 2018 Jun;24(3):238–44 | Epub 21 May 2018
DOI: 10.12809/hkmj177039
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE
Hypospadias surgery in children: improved service model of enhanced recovery pathway and dedicated surgical team
YS Wong, FHKAM (Surgery); Kristine KY Pang, FHKAM (Surgery); YH Tam, FHKAM (Surgery)
Division of Paediatric Surgery and Paediatric Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
 
Corresponding author: Dr YH Tam (pyhtam@surgery.cuhk.edu.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Children in Hong Kong are generally hospitalised for 1 to 2 weeks after hypospadias repairs. In July 2013, we introduced a new service model that featured an enhanced recovery pathway and a dedicated surgical team responsible for all perioperative services. In this study, we investigated the outcomes of hypospadias repair after the introduction of the new service model.
 
Methods: We conducted a retrospective study on consecutive children who underwent primary hypospadias repair from January 2006 to August 2016, comparing patients under the old service with those under the new service. Outcome measures included early morbidity, operative success, and completion of enhanced recovery pathway.
 
Results: The old service and new service cohorts comprised 176 and 126 cases, respectively. There was no difference between the two cohorts in types of hypospadias and surgical procedures performed. The median hospital stay was 2 days in the new service cohort compared with 10 days in the old service cohort (P<0.001). Patients experienced less early morbidity (5.6% vs 15.9%; P=0.006) and had a lower operative failure rate (20.2% vs 44.2%; P<0.001) under the new service than the old service. Multivariable analysis revealed that the new service significantly reduced the odds of early morbidity (odds ratio=0.35, 95% confidence interval=0.15-0.85; P=0.02) and operative failure (odds ratio=0.32, 95% confidence interval=0.17-0.59; P<0.001) in comparison with the old service. Of the new service cohort, 111(88.1%) patients successfully completed the enhanced recovery pathway.
 
Conclusions: The enhanced recovery pathway can be implemented safely and effectively to primary hypospadias repair. A dedicated surgical team may play an important role in successful implementation of the enhanced recovery pathway and optimisation of surgical outcomes.
 
 
New knowledge added by this study
  • Children can be discharged early from hospital after primary hypospadias repairs, regardless of the severity of the hypospadias and the surgical techniques used.
  • Improved operative success of hypospadias repair may be achieved by dedicated hypospadias surgeons.
Implications for clinical practice or policy
  • Primary hypospadias repair in children can be considered as short-stay surgery.
  • Tertiary centres for hypospadias may consider concentration of hypospadias repairs among a few dedicated surgeons.
 
 
Introduction
Hypospadias is a congenital abnormality of the external genitalia in boys, and is defined as an arrest in the embryological development of the urethra, foreskin, and ventral aspect of the penis.1 Hypospadias is characterised by abnormal foreskin with a dorsal hood and an ectopic urethral meatus, which can be located anywhere from the ventral aspect of the glans penis, along the penile shaft, within the scrotum, to the perineum (Fig 1). Hypospadias can be classified broadly into distal, mid-shaft, or proximal types, with the proximal type being the most severe form. In general, more severe forms of hypospadias are associated with a higher incidence and severity of penile ventral curvature (chordee).1
 

Figure 1. Distal hypospadias (left) and proximal hypospadias (right)
Ectopic urethral meatus are indicated by arrows
 
Hypospadias repair is generally recommended in early childhood for improved function and cosmesis.2 Although advances in surgical techniques have resulted in favourable outcomes with high success rates for distal hypospadias repair,3 proximal hypospadias repair remains challenging, and complication rates have been reported to be as high as over 50%.4 Postoperatively, the urethral catheter is usually left in place for free drainage for 5 to 7 days in distal repair5 and from 10 to 14 days in proximal repair.6 In many parts of the world, including North America, patients generally have a very short stay in hospital and are discharged home with urethral catheters in situ.7 In contrast, conventional practice in Hong Kong has been to provide in-patient care after hypospadias surgery until removal of the urethral catheter.
 
The Division of Paediatric Surgery and Paediatric Urology at the Prince of Wales Hospital has been a tertiary referral centre for hypospadias surgery for over two decades. We introduced a new service (NS) model in July 2013, which featured the establishment of a dedicated surgical team and the implementation of an enhanced recovery pathway (ERP). The present study aimed to compare the outcomes of the NS model with those of the old service (OS) model. We hypothesised that ERP implementation by a dedicated surgical team would reduce the risk of early morbidity and increase the operative success of hypospadias repair.
 
Methods
Patients
A historical cohort study was conducted on consecutive patients younger than 18 years who underwent primary repair of hypospadias in our centre from January 2006 to August 2016. The patients were identified using both the ICD-10 (International Classification of Diseases, 10th revision) code related to hypospadias surgery and the registry of operative procedures entry in operating theatres. We used ICD-10 code 752.61, which covered the diagnosis of various types of hypospadias, as well as codes 58.45 and 58.46, which covered various techniques of hypospadias repairs. The patients underwent either one-stage tubularised incised plate (TIP) repair5 8 (Fig 2), or two-stage preputial flap repair9 (Fig 3), as these two techniques had been our standard practice for primary repair of hypospadias from distal to proximal types during the study period. We excluded reoperative hypospadias repairs and repairs with buccal mucosal graft (BMG). Reoperative hypospadias surgery is highly variable in complexity, involves multiple surgical techniques, and is usually investigated separately from primary hypospadias surgery in literature. Children who undergo BMG harvest are generally not considered suitable for early hospital discharge. Moreover, BMG is used rarely in hypospadias surgery, and only under special circumstances. We also excluded minor hypospadias repairs by meatal advancement with glansplasty or meatoplasty alone, as such procedures did not require prolonged urethral catheterisation.
 

Figure 2. Before (left) and after (right) one-stage tubularised incised plate repair
Ectopic urethral meatus are indicated by arrows
 

Figure 3. Before (left) and after (right) two-stage preputial flap repair
Ectopic urethral meatus are indicated by arrows
 
New service model versus old service model
In this study, we assigned patients to two cohorts. The OS cohort was the control cohort comprising patients on whom we operated from January 2006 to June 2013. All the patients in this cohort remained as in-patients until removal of the urethral catheter and received intravenous antibiotics and regular wound care by medical staff in the postoperative period. Six specialist paediatric surgeons were involved in performing the repairs in the OS cohort. The NS cohort comprised patients who underwent surgery in July 2013 or thereafter. Patients in the NS cohort were routinely discharged on postoperative day 2 or, rarely, on postoperative day 3, with their urethral catheters in situ. The dedicated surgical team comprising three (initially only two) specialist paediatric surgeons who subspecialised in paediatric urology provided all perioperative services, including handling of the consent process, surgical repairs, postoperative demonstration of wound care, and explanation of the discharge plan. Parents or main caregivers were instructed to perform saline irrigation to the penile wound at home 3 to 4 times per day. Patients received oral antibiotics and were scheduled to return in a day visit for removal of urethral catheters by a member of the dedicated team. Parents were instructed to call the ward to arrange an unplanned consultation visit if necessary. After urethral catheter removal, patients were followed up at 2 to 4 weeks, 3 months, 6 to 9 months, and then yearly thereafter.
 
Outcome measures
Medical records were retrospectively reviewed and data were collected by the authors, who were not blinded to the type of service model. Data collected were age at time of surgery, type of hypospadias, type of surgical repair, early morbidity, length of hospital stay (LOS), unplanned hospital visits, and follow-up evaluation for long-term complications. Data on the types of hypospadias and surgical techniques were based on the operative findings and surgical procedures documented in the operative records. The presence of any early morbidity was based on investigation results (including urine/wound swab culture) and/or documentations of urethral catheter dislodgement, wound bleeding, or wound gaping in the early postoperative period when the urethral catheter was in situ. The presence of any long-term complications was based on the findings in the latest follow-up visit, or any reintervention/reoperation records subsequent to the primary surgery. When collecting data, we tried to minimise potential bias regarding long-term complications by defining such complications as meatal stenosis, neourethra dehiscence, urethral fistula, urethral stricture or diverticulum, and significant recurrent chordee. All of these long-term complications required re-intervention/reoperation and were documented if present.
 
Primary outcomes of interest were early morbidity and operative failure. Early morbidity was defined by the presence of one or more of the following conditions when the urethral catheter was still in situ: urinary tract infection, catheter dislodgement, and wound-related events (bleeding/infection/gaping). In the OS cohort, early morbidity was detected during the hospitalisation period after hypospadias repair. In the NS cohort, early morbidity was detected at the time of urethral catheter removal or during unplanned hospital visits before the scheduled date of urethral catheter removal.
 
Successful or failed repair was determined during follow-up in those who had undergone TIP repair or had completed both stages of the two-stage repair. Operative failure was defined as the development of one or more of the long-term complications that required reoperation or reintervention. The secondary outcome measure was the successful completion rate of ERP. Failure of ERP was defined as any unplanned hospital visit earlier than the scheduled date for urethral catheter removal. Failure was further subdivided into day visit or overnight stay.
 
Statistical analysis
Discrete variables were expressed as percentage frequency, whereas continuous variables were reported as mean with standard deviation or median with interquartile range (IQR). The two cohorts were compared using Chi squared, Fisher’s exact, Student’s t, and Mann-Whitney U tests, as appropriate. Using the outcomes of early morbidity and operative failure, multivariable analysis was performed using a logistic regression model by the enter method, which estimated the odds ratios (ORs) and 95% confidence intervals (95% CIs) of potential associated factors, including age at the time of surgery, type of hypospadias, type of surgical repair, and the service model. Statistical analysis was performed with SPSS (Windows version 23; IBM Corp, Armonk [NY], United States). A two-tailed P value of <0.05 was considered to be statistically significant. Based on type I error of 0.05 and power of 0.8, 82 to 152 cases in each cohort would be required to show any two-tailed significant difference in the operative failure rates with a difference of 15% to 20% between the two cohorts.
 
Results
There were 302 major primary hypospadias repairs (OS cohort=176; NS cohort=126) eligible for inclusion in the study. We identified 107 cases of reoperative hypospadias repairs and one case of BMG during the study period; these were excluded from this study. No patients were lost to the first follow-up examination after urethral catheter removal. The median follow-up durations of the OS and NS cohorts were 32 (IQR, 20-58) and 20 (IQR, 14-30) months, respectively (P<0.001).
 
Of the NS cohort, 111 (88.1%) patients successfully completed the ERP. Of the 15 patients who failed to complete ERP, 11 (8.7% of total) returned earlier in an unplanned day visit for wound assessment; these patients only required reassurance without any intervention. Four patients (3.2% of total) required additional overnight hospital stay. Reasons for additional overnight stay were minor wound bleeding (n=1), dislodgement of urethral catheter (n=2), and social reasons (n=1). The patient who failed ERP for social reasons was an orphan, and staff at the orphanage found it difficult to perform wound care at their institution.
 
Table 1 summarises the findings comparing patient characteristics and early morbidity between the two cohorts. The median age at the time of surgery was older in the OS than the NS cohort (P<0.001). There was no difference between the two groups in type of hypospadias, type of surgical procedures, and time interval between surgery and urethral catheter removal. The median LOS was 2 days in the NS cohort versus 10 days in the OS cohort (P<0.001). Patients in the NS cohort experienced less early morbidity than those in the OS cohort (5.6% vs 15.9%; P=0.006).
 

Table 1. Results of univariable analysis comparing baseline characteristics and early morbidity of the two cohorts
 
Excluding patients who had received only the first stage of a two-stage repair, 138 and 109 patients of the OS and NS cohort were eligible for assessment of operative success, respectively. Patients in the NS cohort had a lower operative failure rate than those in the OS cohort (20.2% vs 44.2%; P<0.001). Specifically, patients in the NS cohort had a lower incidence of urethral fistula and dehiscence than patients in the OS cohort (P=0.002 and 0.001); there were no differences in the other complications (Table 2).
 

Table 2. Results of univariable analysis comparing operative failure rates of the two cohorts
 
In the multivariable analysis, the NS model was the only factor that was independently associated with reduced odds of early morbidity (OR=0.35, 95% CI=0.15-0.85; P=0.02). The NS model was also associated with reduced odds of operative failure (OR=0.32, 95% CI=0.17-0.59; P<0.001) compared with the OS model. Compared with proximal hypospadias, distal hypospadias had reduced odds for operative failure (OR=0.14, 95% CI, 0.06-0.37; P<0.001). Age at the time of surgery and surgical techniques were not associated with any difference in operative success (Table 3).
 

Table 3. Results of multivariable analysis of independent predictors for early morbidity and operative failure
 
Discussion
The conventional practice of keeping patients in hospital until urethral catheter removal after hypospadias surgery is well reflected from the first annual Surgical Outcome Monitoring and Improvement Programme Report in 2008/09 to the fifth report in 2012/13 issued by the Hong Kong Hospital Authority.10 11 12 13 14 The median LOS after hypospadias surgery performed in Hospital Authority hospitals ranged from 9 to 11 days from 2008 to 2013.10 11 12 13 14 It was a traditionally held belief that Hong Kong parents would not be sufficiently competent to provide proper wound care at home, and that surgical outcomes would be adversely affected if patients were discharged from hospital with the urethral catheter in situ. There was also concern that Hong Kong parents would not welcome the offer of early hospital discharge, given the reality that the actual costs billed to parents for in-patient service in Hospital Authority hospitals are relatively insignificant, compared with other parts of the world where medical insurance covers only very short in-patient care after hypospadias surgery. The present study was the first in Hong Kong to investigate the outcomes of hypospadias surgery after the introduction of an ERP. It is important to note that our findings do not reflect purely the effect of ERP but the effect of an NS model that features ERP implementation by a dedicated surgical team.
 
Our findings demonstrate that ERP can be applied effectively and safely to all children who undergo primary hypospadias repair, regardless of the severity and type of hypospadias. Since its introduction, we have offered ERP to 126 consecutive patients and none of the parents or caregivers have declined the offer. Only one patient discontinued ERP for social reasons, as that child was an institutionalised orphan. Penile wound care does not require special skills and involves only wound irrigation with normal saline or clean water a few times daily. Patients can also be bathed with the urethral catheters in situ. Adequate preoperative counselling and postoperative wound care demonstration by the same surgeons who performed the surgery is the key to promoting the acceptance of ERP among parents.
 
Almost 90% of our patients completed ERP successfully. Among those who failed to complete ERP, none had major adverse events that required surgical intervention and, overall, only 3.2% of patients required additional overnight stay. The median hospital stay of 2 days under the NS model was significantly shorter than the median of 10 days in our OS control cohort. In-patient services are precious resources in our health care system. A much shorter LOS after hypospadias surgery allows for better allocation of health care resources to other service areas in which in-patient care is more indicated.
 
More importantly, our findings suggest that ERP does not increase early morbidity after primary hypospadias repair. On the contrary, the NS model was the only factor that was found to independently predict a reduced risk of early morbidity. Our finding of an early morbidity rate of 5.6% in the NS model is in agreement with the 4.9% reported by a previous study in the United States.15 Our finding that most of the early morbidity in the OS model was wound-related and our observation that, in some of these patients, the wound swab grew Pseudomonas and extended spectrum beta-lactamase Escherichia coli raised the concern of possible hospital-acquired infection. While more evidence is needed to attribute the high early morbidity rate under the OS model solely to the prolonged hospital stay, it follows logically that avoiding unnecessary hospital stay is an effective way to prevent hospital-acquired infection if in-patient care does not give any additional benefits.
 
We found a better outcome after primary hypospadias repair under the NS versus OS model in both univariable and multivariable analyses. This study not only provides evidence that the implementation of ERP did not reduce operative success, but also demonstrates how our centre has responded to the international trend of concentrating hypospadias repairs among dedicated hypospadias surgeons.2 16 17 In recent years, there has been an international call to stop the practice of hypospadias repair by occasional surgeons. Proponents of this view hold that surgeons who perform hypospadias repair should be proficient in using various techniques to correct the full spectrum of hypospadias defects, from distal hypospadias to the most complex proximal type.17 18 The preoperative impression of the ectopic meatal position is not a reliable reflection of the severity of hypospadias, and many cases are found to be more complicated intra-operatively.19 Under the NS model, we abandoned our policy of allowing all paediatric surgical specialists to perform hypospadias surgery; instead, all hypospadias repairs were concentrated among the three specialists who subspecialised in paediatric urology.
 
We believe the improved operative success under the NS model is attributable to the establishment of the dedicated team, which has also introduced some technical modifications in the existing techniques.20 Our overall failure rate of 20.2% of patients requiring reoperation or re-intervention in the NS cohort is in agreement with the 18.1% reported by a national population-based study in the United Kingdom21 and the 24.1% reported by a regional tertiary centre in Europe.22 Both studies included primary repairs of all types of hypospadias performed by multiple techniques, such as those used in the present study.21 22 Previous studies have shown that centres that operate on more than 20 cases per year have a better operative success than those that operate less frequently,21 and surgeons who perform 20 primary repairs annually have reduced odds of failure compared with those who perform 10 per year.23 Although the minimum number of hypospadias repairs per year a surgeon must perform to be considered competent remains debatable, it is recommended that hypospadias repairs be performed by surgeons who perform a high volume of repairs and are intellectually interested in this subject, with continuous review of their own results.17 The current three-member team in our institution strikes a balance between surgical outcomes and other practical issues, such as stable staffing, expertise, training, and succession.
 
Proximal hypospadias has been known to be associated with a higher failure rate in primary repair and a higher reoperation rate than distal hypospadias.24 25 The most recent studies from major centres have unanimously suggested that the failure rate of primary repair of proximal hypospadias has actually been underreported in the literature.6 26 27 Our finding of increased odds of failure in primary repair of proximal hypospadias when compared with the distal type is in agreement with the current evidence. We did not find age at the time of surgery and surgical techniques to be independent predictors of repair failure, and our finding is in agreement with other studies.22
 
We acknowledge the limitations of the retrospective nature of our study and the lack of randomisation. Data are lacking on anatomical variations such as quality of urethral plate and glans size, which may have affected the surgical outcomes. Patients were not randomised by the type of recovery programme and the study participants were assigned to the two cohorts according to the service model at the time. Our results could have been confounded by the effect of accumulating experience in hypospadias surgery throughout the study period. Data were collected by investigators who were not blinded to the types of service models; therefore, there was potential bias in the data collection process, but inter-rater reliability was not examined. As the ERP was implemented at the same time as the establishment of the dedicated team, these two factors could not be analysed separately. Being the more recent cohort, the patients under the NS model had shorter follow-up duration than those under the OS model. However, our median follow-up duration of 20 months in the NS cohort compares favourably to that of many published studies.25
 
Despite these limitations, our findings demonstrate the safety and effectiveness of implementing ERP to primary hypospadias repair for the full spectrum of hypospadias severity. A dedicated surgical team may play an important role in the successful implementation of ERP and optimisation of surgical outcomes.
 
Author contributions
All authors have made substantial contributions to the concept of this study; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Declaration
All authors have no conflicts of interest to disclose. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Ethical approval
The study protocol was approved by the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee. The requirement for patient consent was waived by the ethics board.
 
References
1. Baskin LS, Ebbers MB. Hypospadias: anatomy, etiology, and technique. J Pediatr Surg 2006;41:463-72. Crossref
2. Steven L, Cherian A, Yankovic F, Mathur A, Kulkarni M, Cuckow P. Current practice in paediatric hypospadias surgery; a specialist survey. J Pediatr Urol 2013;9(6 Pt B):1126-30. Crossref
3. Wilkinson DJ, Farrelly P, Kenny SE. Outcomes in distal hypospadias: a systematic review of the Mathieu and tubularized incised plate repairs. J Pediatr Urol 2012;8:307-12. Crossref
4. Long CJ, Canning DA. Hypospadias: are we as good as we think when we correct proximal hypospadias. J Pediatr Urol 2016;12:196.e1-5. Crossref
5. Snodgrass WT, Bush N, Cost N. Tubularized incised plate hypospadias repair for distal hypospadias. J Pediatr Urol 2010;6:408-13. Crossref
6. Pippi Salle JL, Sayed S, Salle A, et al. Proximal hypospadias: a persistent challenge. Single institution outcome analysis of three surgical techniques over a 10-year period. J Pediatr Urol 2016;12:28.e1-7. Crossref
7. Pohl HG, Joyce GF, Wise M, Cilento BJ Jr. Cryptorchidism and hypospadias. J Urol 2007;177:1646-51. Crossref
8. Snodgrass W, Bush N. Tubularized incised plate proximal hypospadias repair: continued evolution and extended applications. J Pediatr Urol 2011;7:2-9. Crossref
9. McNamara ER, Schaeffer AJ, Logvinenko T, et al. Management of proximal hypospadias with 2-stage repair: 20-year experience. J Urol 2015;194:1080-5. Crossref
10. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume One: July 2008-June 2009. Hospital Authority, Hong Kong SAR Government; 2010.
11. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Two: July 2009-June 2010. Hospital Authority, Hong Kong SAR Government; 2011.
12. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Three: July 2010-June 2011. Hospital Authority, Hong Kong SAR Government; 2012.
13. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Four: July 2011-June 2012. Hospital Authority, Hong Kong SAR Government; 2013.
14. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Five: July 2012-June 2013. Hospital Authority, Hong Kong SAR Government; 2014.
15. Meyer C, Sukumar S, Sood A, et al. Inpatient hypospadias care: trends and outcomes from the American nationwide inpatient sample. Korean J Urol 2015;56:594-600. Crossref
16. Springer A, Krois W, Horcher E. Trends in hypospadias surgery: results of a worldwide survey. Eur Urol 2011;60:1184-9. Crossref
17. Snodgrass W, Macedo A, Hoebeke P, Mouriquand PD. Hypospadias dilemmas: a round table. J Pediatr Urol 2011;7:145-57. Crossref
18. Malone P. Commentary to “A standardized classification of hypospadias”. J Pediatr Urol 2012;8:415. Crossref
19. Orkiszewski M. A standardized classification of hypospadias. J Pediatr Urol 2012;8:410-4. Crossref
20. Tam YH, Pang KK, Wong YS, et al. Improved outcomes after technical modifications in tubularized incised plate urethroplasty for mid-shaft and proximal hypospadias. Pediatr Surg Int 2016;32:1087-92. Crossref
21. Wilkinson DJ, Green PA, Beglinger S, et al. Hypospadias surgery in England: higher volume centres have lower complication rates. J Pediatr Urol 2017;13:481.e1-6. Crossref
22. Spinoit AF, Poelaert F, Van Praet C, Groen LA, Van Laecke E, Hoebeke P. Grade of hypospadias is the only factor predicting for re-intervention after primary hypospadias repair: a multivariate analysis from a cohort of 474 patients. J Pediatr Urol 2015;11:70.e1-6. Crossref
23. Lee OT, Durbin-Johnson B, Kurzrock EA. Predictors of secondary surgery after hypospadias repair: a population based analysis of 5,000 patients. J Urol 2013;190:251-5. Crossref
24. Castagnetti M, El-Ghoneimi A. Surgical management of primary severe hypospadias in children: systematic 20-year review. J Urol 2010;184:1469-74. Crossref
25. Pfistermuller KL, McArdle AJ, Cuckow PM. Meta-analysis of complication rates of the tubularized incised plate (TIP) repair. J Pediatr Urol 2015;11:54-9. Crossref
26. Stanasel I, Le HK, Bilgutay A, et al. Complications following staged hypospadias repair using transposed preputial skin flaps. J Urol 2015;194:512-6. Crossref
27. Long CJ, Chu DI, Tenney RW, et al. Intermediate-term followup of proximal hypospadias repair reveals high complication rate. J Urol 2017;197(3 Pt 2):852-8. Crossref

Outcomes of a pharmacist-led medication review programme for hospitalised elderly patients

Hong Kong Med J 2018 Apr;24(2):98–106 | Epub 9 Feb 2018
DOI: 10.12809/hkmj176871
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Outcomes of a pharmacist-led medication review programme for hospitalised elderly patients
Patrick KC Chiu, FRCP (Glasg), FHKAM (Medicine)1; Angela WK Lee, MPharm, RPharmS (Great Britain)2; Tammy YW See, MClinPharm, RPharmS (Great Britain)2; Felix HW Chan, FRCP (Edin, Glasg, Irel), FHKAM (Medicine)1
1 Geriatric Medical Unit, Grantham Hospital, Wong Chuk Hang, Hong Kong
2 Pharmacy, Grantham Hospital, Wong Chuk Hang, Hong Kong
 
Corresponding author: Dr Patrick KC Chiu (chiukc@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Elderly patients are at risk of drug-related problems. This study aimed to determine whether a pharmacist-led medication review programme could reduce inappropriate medications and hospital readmissions among geriatric in-patients in Hong Kong.
 
Methods: This prospective controlled study was conducted in a geriatric unit of a regional hospital in Hong Kong. The study period was from December 2013 to September 2014. Two hundred and twelve patients were allocated to receive either routine care (104) or pharmacist intervention (108) that included medication reconciliation, medication review, and medication counselling. Medication appropriateness was assessed by a pharmacist using the Medication Appropriateness Index. Recommendations made by the pharmacist were communicated to physicians.
 
Results: At hospital admission, 51.9% of intervention and 58.7% of control patients had at least one inappropriate medication (P=0.319). Unintended discrepancy applied in 19.4% of intervention patients of which 90.7% were due to omissions. Following pharmacist recommendations, 60 of 93 medication reviews and 32 of 41 medication reconciliations (68.7%) were accepted by physicians and implemented. After the program and at discharge, the proportion of subjects with inappropriate medications in the intervention group was significantly lower than that in the control group (28.0% vs 56.4%; P<0.001). The unplanned hospital readmission rate 1 month after discharge was significantly lower in the intervention group than that in the control group (13.2% vs 29.1%; P=0.005). Overall, 98.0% of intervention subjects were satisfied with the programme. There were no differences in the length of hospital stay, number of emergency department visits, or mortality rate between the intervention and control groups.
 
Conclusions: A pharmacist-led medication review programme that was supported by geriatricians significantly reduced the number of inappropriate medications and unplanned hospital readmissions among geriatric in-patients.
 
 
New knowledge added by this study
  • This is the first prospective controlled study of the effect of a pharmacist-led medication review programme on medication use and health services utilisation among hospitalised Chinese elderly patients in Hong Kong.
  • The medication review programme led by a clinical pharmacist resulted in a substantial reduction in the use of inappropriate medications among hospitalised elderly patients and all-cause unscheduled readmissions at 1 month after hospital discharge.
Implications for clinical practice or policy
  • A pharmacist-led medication review programme is an important strategy that can enhance the safety and quality of prescription among elderly patients in hospital.
  • It is strongly recommended that these programmes be standardised and implemented in all medical and geriatric wards in Hong Kong.
 
 
Introduction
Elderly patients have multiple co-morbidities and they are consequently prone to multiple medication use. Inappropriate medication use is common among hospitalised older adults. The number of drugs taken is one of the important determinants of risk for receiving an inappropriate medication.1 There is a high prevalence of unnecessary drug use in frail older people. In one hospital study, 44% of patients were prescribed at least one unnecessary drug, with the most common reason being lack of indication.2 The most commonly prescribed unnecessary drug classes were gastrointestinal, central nervous system, and therapeutic nutrients/minerals.2 Appropriate use of drugs is particularly important in the frail older people who are especially at risk of adverse drug reactions.3 It has been shown that implementation of a clinical pharmacist service has a positive effect on medication use and health care service utilisation among hospitalised patients.4 5 A local study in a geriatric hospital demonstrated the effectiveness of a drug rationalisation programme with involvement of a clinical pharmacist in reducing the incidence of polypharmacy and inappropriate medications.6 Interacting with the health care team on patient rounds, interviewing patients, reconciling medications, and providing patient discharge counselling and follow-up all resulted in improved outcomes.7 It is for this reason that patient safety strategies encourage the use of medication reconciliation and clinical pharmacists in health care systems to reduce adverse drug events.8 9 10
 
There is not much information about the effectiveness of a medical review programme among hospitalised elderly patients in Hong Kong. Two recent local reports that examined the effects of a clinical pharmacist–led medication review on hospital readmissions showed conflicting results and did not specifically address elderly patients.11 12 We therefore conducted a prospective controlled study to investigate the effectiveness of a comprehensive pharmacist intervention on medication use and hospital readmission among a group of geriatric in-patients in Hong Kong.
 
Methods
This prospective controlled study was conducted in the geriatric unit of a regional hospital in Hong Kong. The unit has 38 in-patient beds and admits older people aged 65 years or above who are transferred from an acute hospital after initial stabilisation of medical and/or geriatric problems. The unit admits more than 1000 patients per year and provides medical treatment, rehabilitation, and discharge planning services by a multidisciplinary team composed of a geriatrician, residents, nurses, physiotherapists, occupational therapists, and medical social workers. All patients admitted to the unit during December 2013 to September 2014 were included. Patients were excluded if they refused to participate, were terminally ill with a life expectancy of less than 3 months, or if they had already received pharmacist intervention in another hospital prior to this admission. Eligible subjects were assigned to an intervention or control group according to the admission day of the week. Those who were admitted on Monday through Thursday were assigned to the intervention group, and those admitted on Friday through Sunday to the control group. This arrangement was to ensure that pharmacist intervention could be initiated promptly within 48 hours of patient admission. Demographic data, functional status, co-morbidities, and number of drugs on admission were collected at admission.
 
The intervention was conducted by a pharmacist who was present in the unit from Monday to Saturday. The pharmacist provided pharmaceutical care from admission to discharge. Interventions performed by the pharmacist consisted of the following:
 
(1) Medication reconciliation on admission to identify unintended discrepancies between medications prescribed on admission and the usual medications prior to admission—sources to assist medication reconciliation included: electronic patient record; patient’s ward case notes; interview with patient and/or patient carer. The number and type of unidentified discrepancies were recorded.
 
(2) Medication review to check for medication appropriateness on admission and also at discharge—medication appropriateness was assessed by the Medication Appropriateness Index (MAI).13 There are 10 criteria to assess for appropriateness, namely indication, effectiveness, dosage, correct direction, practical direction, drug-drug interaction, drug-disease interaction, duplication, duration, and expense. For a drug item coded as ‘inappropriate’, relative weights for each criterion would apply. A sum of MAI scores could then be calculated to give a score ranging from 0 to 18. The higher the score, the more inappropriate the drug. Recommendations from the pharmacist after the reconciliation and medication review in the intervention group were then communicated to the in-charge doctor via a written note in the medical records. Recommendations were reinforced verbally if deemed appropriate by the pharmacist.
 
(3) Pharmacist counselling on admission and also at discharge was provided to improve patients’ drug knowledge to ensure proper use of drugs and compliance after discharge. A discharge counselling service was provided for all patients who returned home. The counselling included any changes to drug regimen; an explanation of each drug’s indication; any untoward effects that might occur and when to seek medical advice; and drug storage and administration instructions. To ensure patient understanding, written information such as patient information leaflets were given to patients and their carers to remind them of the correct drug regimen. If the patient was illiterate, a simple diagram was drawn on drug labels to demonstrate the time of day and number of tablets to be taken. If necessary, individualised pictorial schedules with drug images and administration instructions could be produced for patients and their carers. The assistance of a family member or external care services such as a community nurse was enlisted if the patient was found to have compliance issues.
 
The control group received routine clinical services. Records of the control group were retrospectively reviewed by the pharmacist after patient discharge to check for medication appropriateness on admission and also at discharge. The primary outcome measure was the appropriateness of prescription as measured by the MAI. Secondary outcomes included the acceptance rate by physicians, number of subjects with unintended discrepancies, patient satisfaction with the programme (for those home-living only), and unplanned hospitalisations 1 and 3 months after discharge.
 
A sample size of 98 patients per group was required to have 85% power to detect an effect size of 0.9 on the MAI. Our sample size was finally set at 210 patients to account for loss of participants due to dropout or death. This sample size was comparable with a study by Spinewine et al14 in which MAI was used as one of the tools to assess appropriateness of prescribing in an acute geriatric care unit and 203 patients were recruited. Our study included 212 patients and was expected to have adequate statistical power to detect differences between groups. Descriptive analyses were performed and included the number and types of unintended discrepancies, MAI score upon admission and at discharge, types of drug-related problems, number of interventions made by pharmacists, and number of recommendations accepted by doctors and implemented. Outcomes for the two groups before and after the programme were compared using the t test and Chi squared test. The Statistical Package for the Social Sciences (Windows version 17.0; SPSS Inc, Chicago [IL], United States) was used and a P value of <0.05 was regarded as statistically significant. The study was approved by the Cluster Research Ethics Committee of the Hospital Authority Hong Kong West Cluster. Written consent was obtained from the patient or their caregiver. The absence of pharmacist intervention in the control group was considered acceptable because a pharmacy service was not a part of routine care at the institution.
 
Results
Figure 1 summarises the patient flow from recruitment to hospital discharge, the components of the medication review programme, and the planned outcome measures. A total of 212 patients were recruited. There were 108 subjects in the intervention group and 104 in the control group (Fig 2). There were no statistical differences in the baseline characteristics of patients (Table 1).
 

Figure 1. Patient flow of the medication review programme from patient recruitment to patient discharge
 

Figure 2. Patient flow diagram
 

Table 1. Baseline demographics and characteristics of the intervention and control groups
 
Appropriateness of prescription
On admission, 51.9% (56/108) of the intervention group and 58.7% (61/104) of the control group had at least one drug classified as inappropriate (P=0.319). Overall, 1996 drug items were reviewed by a pharmacist on admission of which 1020 were from the intervention group and 976 from the control group. Among them, 9.3% and 11.1% of the drugs, respectively, were classified as inappropriate (P=0.282). In the intervention group, 93 recommendations were made by the pharmacist of which 60 (64.5%) were accepted by the physicians and implemented. The mean (standard deviation) MAI score per patient was 2.19 (3.03) in the intervention group and 2.28 (3.09) in the control group (P=0.841). The mean MAI score per drug was 0.23 (0.30) in the intervention group and 0.25 (0.31) in the control group (P=0.628) [Table 2].
 
After the program and at discharge, the proportion of subjects with inappropriate medications in the intervention group was significantly lower than that in the control group (28.0% vs 56.4%; P<0.001). Among the 1999 drug items reviewed by the pharmacist on patient discharge, 3.5% (37 of 1048) of the intervention group and 9.7% (92 of 951) of the control group were classified as inappropriate (P<0.001). The intervention group also had a significantly lower MAI score per patient (0.95 (2.02) vs 2.02 (2.53); P<0.001) and MAI score per drug (0.09 (0.17) vs 0.24 (0.30); P<0.001) implying a significant reduction in medication inappropriateness after the pharmacist medication review (Table 2).
 

Table 2. A comparison of the number of subjects with inappropriate medications and the MAI scores between the intervention and control groups on admission and at discharge
 
Types of inappropriateness according to the MAI in the two groups are illustrated in Figure 3. In both the intervention and control groups, the common causes were indication, effectiveness, dosage, practical direction, duration, and expense. After the programme, there was a significant reduction in the number of these drug-related problems in the intervention group.
 

Figure 3. Comparison of the types of inappropriate medication use between the intervention and control groups on admission and at discharge (paired t test)
 
Unintended discrepancy of medications
Among the 108 subjects in the intervention group, 19.4% had at least one unintended discrepancy in medications, involving a total of 43 drug factors. The majority (90.7%) of these factors were omission of drugs, and 4.6% were due to inappropriate dosages. Of all the drug factors involved, 69.8% involved prescribed drugs from hospitals, 25.6% were from a private clinic, and 4.6% were over-the-counter drugs. Overall, 41 recommendations were made, of which 32 (78.0%) were accepted by physicians and implemented.
 
Patient satisfaction
Contact was made with 50 of the 90 non-institutionalised subjects 1 month after discharge to assess satisfaction with the programme. Of those contacted, 98.0% were satisfied with the programme and only one (2.0%) patient expressed a neutral opinion.
 
Impact on health care services utilisation and mortality
There were no statistical differences in the length of hospital stay, in-patient mortality, or mortality at 1 month or 3 months after discharge. There was also no statistical difference in the number of attendances at the accident and emergency department 1 month or 3 months after discharge or in the unplanned hospital readmission rate at 3 months after discharge. The unplanned hospital readmission rate 1 month after discharge, however, was significantly lower in the intervention group than that in the control group (13.2% vs 29.1%; P=0.005) [Table 3].
 

Table 3. Comparison of the impact on health services utilisation and mortality between the intervention and control groups
 
Discussion
To the best of our knowledge, this is the first local prospective controlled study to investigate the effectiveness of a pharmacist-led medication review programme on medication appropriateness and clinical outcomes among geriatric in-patients in Hong Kong. This study has demonstrated superior outcomes that favour a pharmacist-led intervention. There was a substantial reduction in the use of inappropriate medications and all-cause unscheduled readmissions 1 month after hospital discharge. Nonetheless, analysis of length of hospital stay, number of all-cause emergency department visits, and mortality rate favoured neither the intervention nor the usual pharmacist care.
 
This study showed that one in five geriatric in-patients had an unintended medication discrepancy on admission. This figure was slightly higher than that found in a group of 3317 hospitalised medical patients (13%) over 1 year in an acute hospital in Hong Kong by Kwok et al.15 Subjects in our study were all elderly patients, whereas those in Kwok et al’s study were adults of all ages. Elderly subjects tend to have polypharmacy and thus are more vulnerable to unintended medication discrepancy when they move in and out of hospital or are transferred to another health care unit for further care. Unjustifiable medication discrepancies account for more than half of the medication errors that occur during transition of care and up to one third have the potential to cause harm.16 17 This does not bode well for our elderly patients with multiple co-morbidities.
 
Up to 30% of the discrepancies in our study involved medications that had been prescribed by private practitioners or purchased over-the-counter. Unlike medications prescribed from the Hospital Authority, these medications might be overlooked unless the admitting doctor specifically asks for a detailed drug history from the patient. Knowing the medication history and hence resuming these medications are important if new health problems are to be prevented. Pharmacist-led medication reconciliation is therefore a critical process that can enhance patient medication safety by compiling a complete and accurate medication list for patients in hospital.
 
This study revealed that more than half of the subjects (55.2%) received inappropriate medications. The majority of reasons for inappropriateness related to effectiveness, dosage, practical directions, and expense as reflected by the MAI. The inappropriate dosage and the questionable effectiveness might lead to not only failed pharmacological effects, but also potentially an untoward adverse drug reaction, especially in elderly individuals with pre-existing organ dysfunction.18 When a medication is not used according to the practical directions, it may lead to patient non-compliance. Optimising outcomes while reducing costs are the keys for medication management in today’s health care environment.19 Often there are several choices of drugs available to treat a disease or health condition and some are more expensive than others. The involvement of a ward-based pharmacist to review medication can enhance the use of appropriate medications in hospitalised patients and potentially reduce medication costs.
 
Following the medication review (60/93) and medication reconciliation (32/41), there were 92 recommendations that were accepted by the physician. The overall acceptance rate by physicians and the implementation of pharmacist recommendations in our study was 68.7% (92/134). This figure ranged from 39% to 100% in a previous systematic review of 32 studies.4 Our study did not specifically record recommendations accepted by physicians but not implemented. Hence the acceptance rate in our study may be underestimated. Nevertheless, the clinical pharmacist is encouraged to discuss the medication-related problems in person with the physician as well as contacting the patient in order to enhance the implementation rate.4
 
Pharmacy departments within the public hospital system in Hong Kong have strived to implement the aforementioned patient safety strategies in different specialties. Nonetheless, this is not a standard practice simply because of insufficient pharmacist staffing resources. In some hospitals, a pharmacist service is provided in wards, but this does not apply in all cases and is not standardised. Experience of a pharmacist-led medication reconciliation service from an acute teaching hospital in Hong Kong showed promising results over a 1-year trial run with high acceptance and recognition by other health care professionals.16 It is hoped that the clinical role of clinical pharmacists in patient medication management in hospitals can be encouraged. Another local study has demonstrated a positive impact on medication safety in patients with diabetes by pharmacists’ intervention in collaboration with a multidisciplinary team.20 The feasibility of incorporating a pharmacist as part of a multidisciplinary team of health care professionals must be explored in geriatric wards in Hong Kong. With increasing life expectancy, the expanding elderly population will equate to an increase in morbidity and mortality owing to drug-related problems where the need for trained health care professionals to perform medication reviews will be in even greater demand. To enhance safe drug use with limited resources, a systematic approach must be adopted to cover all aspects that affect drug therapy.
 
In terms of the impact on health care services utilisation, a recent systematic review and meta-analysis of the effectiveness of a pharmacist-led medication reconciliation programme revealed a substantial reduction in the rate of all-cause readmissions (19%), all-cause emergency department visits (28%), and adverse drug event–related hospital visits (67%).21 Our study revealed a significant reduction in unplanned hospital admissions (all-cause admission) at 1 month but not at 3 months. This implication might be due to an inadequate sample size to show the difference at 3 months. Alternatively, it might also imply that pharmacist intervention needs to be continued after patient discharge in order to have a sustained effect. This is supported by a study by Schnipper et al22 in which pharmacist intervention after patient discharge was associated with a lower rate of preventable adverse drug events 30 days after hospital discharge.
 
During the pharmacist review, cost-effectiveness of drug use was assessed through MAI. Alternative options such as less-expensive formulations or drugs but of the same quality would be recommended to the doctor in-charge. This was a means of encouraging cost-effective use of drugs in a hospital. Furthermore, the reduction in unscheduled hospital readmissions in the intervention group implies a potential saving in hospital costs. Although a detailed analysis was not performed in this study, a rough estimation is that nearly HK$2 million may be saved annually as a result of lower drug costs and reduced hospital admissions, even after considering the cost of employing a pharmacist. The estimation was based on the following calculations. The estimated drug saving as a result of a switch to a more cost-effective alternative was HK$7500 among the 108 patients in the intervention group. This can be projected to a saving of about HK$69 500 in a unit that admits 1000 patients annually. In the current study, there were 16 fewer readmissions in the intervention group compared with the control group. Assuming a daily cost of an acute hospital bed is HK$4680 and the mean length of hospital stay is 3 days, this equates to a potential saving of about HK$2 080 000 per year in a unit that admits 1000 patients annually. If it is assumed that a pharmacist spends 30 minutes for each patient at an hourly salary of HK$433, the projected cost of an additional pharmacist to run the intervention would be HK$216 500 per year. The net annual saving of this programme to serve 1000 patients in this unit would thus still be close to HK$2 million.
 
This study had several limitations. First, a substantial proportion (35%) of all the admitted patients were not screened by a pharmacist on admission. This was due to a temporary pause in subject recruitment when patients were admitted on public holidays, when the pharmacist was on holiday or when she had to relieve another pharmacist in the hospital. Moreover, a substantial proportion (44%) of eligible subjects were not included owing to no consent or refusal. These factors might have resulted in selection or self-selection bias. Second, subject recruitment was not randomised, but done according to the day of admission. This might be a source of bias. Nevertheless, this would have minimal influence on the outcomes, as the baseline characteristics of the intervention and control groups were comparable. Third, the pharmacist who carried out the review and data extraction was not blinded to the study hypothesis and the group status of the subjects. This could potentially lead to information bias, although this might be partially offset by the fact that the majority of the information or data on the outcome measures were taken with reference to a well-established and validated tool. Fourth, this study was performed in a single unit, so generalisation to other settings is not possible. Fifth, MAI is an implicit tool that is subjective. A single pharmacist as the rater might limit the reliability of the assessment results. Nevertheless, the more explicit tools of STOPP/START criteria23 had also been referred to in addition to the MAI during the review process. Sixth, this study only addressed appropriateness of drug use, whereas underuse of drugs was not investigated. Finally, this study could not conclude a causal relationship between the reduction in inappropriate medications and the reduction in unscheduled hospital readmissions because there were several components in the intervention that included a medication review, medication reconciliation, and discharge counselling. It is difficult to be certain which of these components alone or in combination gave rise to the positive outcome of this study.
 
On the other hand, there were several strengths in this study. This was the first prospective controlled study of the effect of a pharmacist-led medication review programme on medication use and health services utilisation involving over 200 Chinese elderly patients in Hong Kong. Second, a well-validated tool was used to assess medication appropriateness. The use of the MAI tool focused on the patient and the entire medication regimen. Third, there was a comprehensive review of outcomes including quality of prescribing, health services utilisation, mortality, length of hospital stay, and patient satisfaction.
 
Conclusions
This study supported the role of a hospital-based clinical pharmacist to enhance appropriate medication use among elderly Chinese in-patients. A systematic medication review programme in a geriatric unit resulted in a reduced number of drug omissions and fewer inappropriate medications. The service provided by the clinical pharmacist and supported by geriatricians was welcomed by patients and their carers. Together with the potential to reduce hospital readmissions and their associated cost, it is hoped that an in-hospital pharmacist-led medication review programme can be recognised as one of the important strategies to enhance the safety and quality of prescription among elderly patients in hospitals. It is strongly recommended that these programmes be standardised and implemented in all medical and geriatric wards in Hong Kong. Future studies should recruit a larger sample size in a randomised controlled design in other geriatric hospital settings to reiterate our findings. Furthermore, these studies might consider including adverse drug event–related hospital visits as one of the outcome measures.
 
Declaration
All authors have disclosed no conflicts of interest.
 
References
1. Onder G, Landi F, Cesari M, Gambassi G, Carbonin P, Bernabei R; Investigators of the GIFA Study. Inappropriate medication use among hospitalized older adults in Italy: results from the Italian Group of Pharmacoepidemiology in the Elderly. Eur J Clin Pharmacol 2003;59:157-62. Crossref
2. Hajjar ER, Hanlon JT, Sloane RJ, et al. Unnecessary drug use in frail older people at hospital discharge. J Am Geriatr Soc 2005;53:1518-23. Crossref
3. Routledge PA, O’Mahony MS, Woodhouse KW. Adverse drug reactions in elderly patients. Br J Clin Pharmacol 2004;57:121-6. Crossref
4. Graabaek T, Kjeldsen LJ. Medication reviews by clinical pharmacists at hospitals lead to improved patient outcomes: a systematic review. Basic Clin Pharmacol Toxicol 2013;112:359-73. Crossref
5. Gillespie U, Alassaad A, Henrohn D, et al. A comprehensive pharmacist intervention to reduce morbidity in patients 80 years or older: a randomized controlled trial. Arch Intern Med 2009;169:894-900. Crossref
6. Chan FH, Pei CK, Chiu KC, Tsang EK. Strategies against polypharmacy and inappropriate medication—are they effective? Australas J Ageing 2001;20:85-9. Crossref
7. Kaboli PJ, Hoth AB, McClimon BJ, Schnipper JL. Clinical pharmacists and inpatient medical care: a systematic review. Arch Intern Med 2006;166:955-64. Crossref
8. The ACHS EQuIP5 (5th edition of the ACHS Evaluation and Quality Improvement Program) clinical standard 1.5, criterion 1.5.1.: Medication are managed to ensure safe and effective consumer/patient outcomes. Sydney: The Australian Council on Health Care Standards; 2010.
9. Medication reconciliation. Patient Safety Network. Agency for Healthcare Research and Quality. US Department of Health & Human Services. Available from: http://psnet.ahrq.gov/primer.aspx?primerID=1. Accessed 11 Jun 2017.
10. Gurwitz J, Monane M, Monane S, Avorn J. Polypharmacy. In: Morris JN, Lipsitz LA, Murphy K, Bellville-Taylor P, editors. Quality care in the nursing home. St. Louis, MO: Mosby-Year Book; 1997: 13-25.
11. Wong CY, Lee TO, Lam MP. Pharmacist discharge intervention programme to reduce unplanned hospital use in patients with polypharmacy. Hong Kong Pharm J 2017;24(Suppl 1):S18.
12. Chan HH. To reduce avoidable readmission of patients who are categorized as high risk by 30-day hospital readmission model at medical ward of United Christian Hospital through medication reconciliation and discharge counseling. Hong Kong Pharm J 2017;24(Suppl 1):S21.
13. Hanlon JT, Schmader KE, Samsa GP, et al. A method for assessing drug therapy appropriateness. J Clin Epidemiol 1992;45:1045-51. Crossref
14. Spinewine A, Swine C, Dhillon S, et al. Effect of a collaborative approach on the quality of prescribing for geriatric inpatients: a randomized, controlled trial. J Am Geriatr Soc 2007;55:658-65. Crossref
15. Kwok CC, Mak WM, Chui CM. Implementational experience of medical reconciliation in Queen Mary Hospital. Hong Kong Pharm J 2009;16:50-2.
16. Rozich JD, Howard RJ, Justeson JM, Macken PD, Lindsay ME, Resar RK. Standardization as a mechanism to improve safety in health care. Jt Comm J Qual Saf 2004;30:5-14. Crossref
17. Cornish PL, Knowles SR, Marchesano R, et al. Unintended medication discrepancies at the time of hospital admission. Arch Intern Med 2005;165:424-9. Crossref
18. Cameron KA. Caregivers’ guide to medications and aging. National Center on Caregiving, Family Caregiver Alliance 2004. Available from: https://www.caregiver.org/caregiver%CA%BCs-guide-medications-and-aging. Accessed 11 Jun 2017.
19. Splawski J, Minger H. Value of the pharmacist in the medication reconciliation process. P T 2016;41:176-8.
20. Chung AY, Anand S, Wong IC, et al. Improving medication safety and diabetes management in Hong Kong: a multidisciplinary approach. Hong Kong Med J 2017;23:158-67. Crossref
21. Mekonnen AB, McLachlan AJ, Brien JA. Effectiveness of pharmacist-led medication reconciliation programmes on clinical outcomes at hospital transitions: a systematic review and meta-analysis. BMJ Open 2016;6:e010003. Crossref
22. Schnipper JL, Kirwin JL, Cotugno MC, et al. Role of pharmacist counseling in preventing adverse drug events after hospitalization. Arch Intern Med 2006;166:565-71. Crossref
23. Lam MP, Cheung BM. The use of STOPP/START criteria as a screening tool for assessing the appropriateness of medications in the elderly population. Expert Rev Clin Pharmacol 2012;5:187-97. Crossref

Intra-operative periarticular multimodal injection in total knee arthroplasty: a local hospital experience in Hong Kong

Hong Kong Med J 2018 Apr;24(2):145–51 | Epub 14 Mar 2018
DOI: 10.12809/hkmj176804
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Intra-operative periarticular multimodal injection in total knee arthroplasty: a local hospital experience in Hong Kong
Jason CH Fan, FHKAM (Orthopaedic Surgery)
Department of Orthopaedics and Traumatology, Alice Ho Miu Ling Nethersole Hospital, Tai Po, Hong Kong
 
Corresponding author: Dr Jason CH Fan (fchjason@gmail.com)
 
 Full paper in PDF
 
Abstract
Introduction: Data from a local report revealed the superior outcome of regional anaesthesia and analgesia compared with general anaesthesia and intravenous patient-controlled analgesia in total knee arthroplasty. This retrospective study aimed to assess the efficacy of intra-operative periarticular multimodal injection in improving postoperative pain and reducing morphine consumption with patient-controlled analgesia after total knee arthroplasty in patients with knee osteoarthritis.
 
Methods: From July 2005 to May 2009, 213 total knee arthroplasties without intra-operative periarticular multimodal injection (control group) were performed at a local hospital. From June 2009 to December 2012, 185 total knee arthroplasties were performed with intra-operative periarticular multimodal injection (cocktail group). The inclusion criteria were osteoarthritis of the knee, single method of anaesthesia (general or neuraxial), simple total knee arthroplasty without any metal augmentation or constraint, and postoperative patient-controlled analgesia. Postoperative patient-controlled morphine doses were compared.
 
Results: A total of 152 total knee arthroplasties were recruited to the cocktail group, and 89 to the control group. Duration of tourniquet application and preoperative knee score did not significantly correlate with morphine consumption by patient-controlled analgesia. Multimodal injection significantly decreased such consumption for 36 h. When injection was separately analysed for general and neuraxial anaesthesia, the effect lasted for 42 h and 24 h, respectively.
 
Conclusion: Intra-operative periarticular multimodal injection decreased morphine consumption for up to 42 h postoperatively.
 
 
New knowledge added by this study
  • Intra-operative periarticular multimodal injection in total knee arthroplasty could decrease parenteral morphine consumption for up to 42 hours.
Implications for clinical practice or policy
  • Intra-operative periarticular multimodal injection should be adopted as a standard local practice for postoperative pain control. This practice may be extended to operations other than total knee arthroplasty.
 
 
Introduction
Postoperative pain following total knee arthroplasty (TKA) is reported to be severe in approximately 60% of patients and moderate in approximately 30%.1 It is associated with arthrofibrosis and diminished range of motion.2 3 Good pain relief is important for rehabilitation following TKA.4 Many modes of perioperative and postoperative analgesia are available, and involve various combinations of systemic and regional analgesia. Intra-operative periarticular multimodal drug injection has been well documented as an excellent method to alleviate postoperative pain following TKA.5 6 7 Nonetheless, a previous retrospective study5 and a randomised trial6 that analysed two different groups of patients with multiple diagnoses and multiple anaesthetic methods revealed that the effect of periarticular injection might have been affected by different causes of end-stage arthritis leading to TKA. Different anaesthetic methods could also have affected patients’ perception of pain and parenteral morphine consumption.
 
In 2006, Chu et al8 reported the superior outcome of regional anaesthesia and regionally delivered analgesia compared with general anaesthesia (GA) and intravenous patient-controlled analgesia (PCA) in TKA at the Alice Ho Miu Ling Nethersole Hospital (AHNH). Since June 2009, intra-operative periarticular multimodal injection (IPMI) consisting of an opioid (morphine), a long-acting local anaesthetic (levobupivacaine) and epinephrine, has been administered by surgeons to control postoperative pain following TKA. This retrospective cohort study analysed the efficacy of IPMI in TKA and also its effect following different types of anaesthesia.
 
Methods
Perioperative pain management
Before June 2009, postoperative pain following primary TKA was managed by a combination of parenteral and oral analgesia. The anaesthetist determined the choice of parenteral analgesia that included regular or as-required subcutaneous morphine injection, PCA with intravenous morphine injection, or epidural analgesia (EpA). Oral paracetamol 1 g every 6 h was prescribed to all patients from day 1 to 3. Since June 2009, IPMI has been routinely added, and comprises 20 mL of 0.5% levobupivacaine, 1 mL of 5 mg/mL morphine, 2 mL of 1:10000 adrenaline, and 17 mL of normal saline. In this study, half of this 40-mL mixture was injected into the posterior capsule, collaterals, and quadriceps incision before implantation of the prosthesis. The other half was injected into the subcutaneous tissue after suturing of the arthrotomy. All patients with PCA were assessed hourly for the first 24 h to monitor vital signs, pain score, and patient-controlled analgesia morphine consumption (PCAMC), and thereafter every 6 h for 2 more days.
 
Patient selection
From July 2005 to May 2009, 213 TKAs without IPMI (control group) were performed at AHNH. They included 196 knees with osteoarthritis (OA) and 17 knees with rheumatoid arthritis. From June 2009 to December 2012, 185 TKAs were performed with IPMI (cocktail group). There were 175 OA knees, nine rheumatoid arthritis knees, and one Charcot knee.
 
All TKAs were performed through an anterior midline incision and medial parapatellar arthrotomy with tourniquet pressure of 300 mm Hg. A cemented posterior stabilised model was used in all cases except for two cases in the control group and nine cases in the cocktail group where a semi-constrained TKA was performed. All operations were performed under GA or neuraxial anaesthesia (NeA) that was either combined spinal epidural or spinal anaesthesia. Four TKAs in the cocktail group and four in the control group were performed with combined GA and NeA. A closed-suction surgical drain was inserted and was routinely removed on postoperative day 2.
 
For postoperative pain control in the control group, PCA was used in 112 TKAs, EpA in 66 TKAs, and subcutaneous morphine injections in 10 TKAs. A 4-point pain scale was completed by a pain nurse to assess pain in 189 PCA patients before October 2008 and a 10-point pain scale used in 23 PCA patients thereafter. In the cocktail group, 152 TKAs were managed with PCA, three with EpA, and three with subcutaneous morphine injections. Pain in all PCA patients was assessed by a 10-point pain scale.
 
The inclusion criteria for this study were OA of the knee, single method of anaesthesia of either GA or NeA, simple TKA without any metal augmentation or constraint, and postoperative PCA. The patients in the control group who were assessed by the 10-point pain scale were excluded to ensure a common pain assessment tool for each group.
 
Method of data retrieval, analysis, and study hypothesis
This was a retrospective cohort observational study carried out in accordance with the principles outlined in the Declaration of Helsinki. Informed patient consent was not required because it was a record-based study that revealed no individual identities or sensitive individual information. The medical records and electronic patient records were traced and the necessary data—including demographic data, TKA model and anaesthetic method, first 72-hour pain score and morphine consumption, and postoperative complications—were entered into an electronic file by a single member of staff blinded to the study hypothesis. The accuracy of the data was selectively double-checked by the author. To enable comparison, pain score was divided by 4 when the 4-point scale was used and by 10 for the 10-point scale. Statistical Package for the Social Sciences (Windows version 13.0; SPSS Inc, Chicago [IL], United States) was used for analysis. The null hypothesis was that IPMI would not alleviate postoperative pain and would not reduce PCAMC. The Chi squared test and two-tailed independent t test were used to analyse categorical and continuous data, respectively. The Pearson correlation test was used to detect any relationship between cumulative PCAMC and tourniquet time, and between PCAMC and preoperative knee score. Statistical significance was set at P<0.05.
 
Results
Perioperative variables
A total of 152 knees (134 patients) in the cocktail group and 89 knees (76 patients) in the control group were recruited (Fig 1). Table 1 shows the demographic data and clinical characteristics of patients, and Table 2 shows the models of primary TKAs and anaesthetic methods. There was no statistically significant difference in age, sex, the side operated on, and mean preoperative knee score or function score between the cocktail and control groups. Tourniquet time was significantly longer in the control group (P<0.05). There was no correlation between tourniquet time and PCAMC for any postoperative period (all correlation coefficients <0.1 and P>0.05). This indicated that tourniquet time was not confounding. Preoperative knee score was not correlated with PCAMC (all correlation coefficients <0.2 and P>0.05). Comparison of the number of Press Fit Condylar Sigma and non–Press Fit Condylar models between the two groups revealed a statistical significance (P<0.001). However, all these models substitute for the posterior cruciate ligament and have a similar design. They were all used in primary simple TKA, and model type would not have caused any difference in early postoperative pain perception.
 

Figure 1. Knee recruitment in the control group and cocktail group
 

Table 1. Patient and clinical characteristics, by study group
 

Table 2. Total knee arthroplasty model and anaesthesia, by study group
 
Cumulative patient-controlled analgesia morphine consumption
The mean cumulative PCAMC in both the cocktail and control groups increased gradually until 72 h postoperatively (Fig 2). The difference between the two groups reached statistical significance in the first 36 h. When effects of GA and NeA were reviewed separately, significantly less PCA morphine was required in the cocktail group than in the control group for the first 42 h (after GA) and 24 h (after NeA).
 

Figure 2. Postoperative morphine consumption by patient-controlled analgesia after total knee arthroplasty
 
Pain scale and complication
Figure 3 shows a decreasing severity of pain for both groups in the initial 72 h after surgery. There was no statistically significant difference between groups when TKA was performed under GA. In patients who underwent TKA under NeA, patients in the control group had a lower pain scale score by 0.1 at 12 h and from 24 to 48 h compared with the cocktail group, although this was gradually reversed up to 72 h. There were no adverse effects or complications as a result of IPMI.
 

Figure 3. Postoperative pain scale score after total knee arthroplasty
 
Discussion
Severe pain following TKA may be related to bone or soft tissue trauma or hyperperfusion following tourniquet release.6 Surgical difficulty in TKA has also been found to be related to postoperative pain9 and related to bone loss, severe deformity, flexion contracture, and poor range, all of which contribute to a low preoperative knee score. Nonetheless, in this study, the duration of tourniquet application was not significantly correlated with morphine consumption; and preoperative knee score was not correlated with PCAMC.
 
Pain management for TKA should start preoperatively and intra-operatively. The preemptive use of analgesia has been shown to prevent central sensitisation and improve postoperative pain control.10 11 12 Busch et al6 conducted a randomised trial of periarticular multimodal drug injection of ropivacaine, ketorolac, epimorphine, and epinephrine in 64 TKA patients. They reported significantly lower pain scores, increased patient satisfaction scores, and decreased requirement for PCA in the first 24 hours after surgery. In another randomised trial of periarticular injection of bupivacaine, fentanyl, and methylprednisolone in either side of bilateral TKAs in 40 patients, pain scores were significantly lower, and active knee flexion ranges were greater until the fourth week after surgery.13 Maheshwari et al7 emphasised the importance of periarticular injection in multimodal pain management following TKA at the Ranawat Orthopaedic Center, United States, and PCA was no longer used because of the high rates of systemic opioid side-effects.
 
The AHNH includes morphine in multimodal injections because opioid receptors are present in peripheral inflamed tissue.14 15 They are expressed within hours of surgical trauma and are thought to be responsible for afferent sensory input to the central nervous system.16 17 The injection also includes levobupivacaine, which is pharmacokinetically similar to bupivacaine. It is a pure left-isomer and has less cardiac and central nervous system toxicity.18 Corticosteroid was not added to the injection, although studies19 20 have shown that methylprednisolone in periarticular injections in total joint surgeries caused no delayed wound healing or wound infection. Mullaji et al13 advocated cautious use of steroid for fear of increasing the risk of surgical site infection in patients who (1) had prior open surgical procedures, (2) were undergoing revision TKA, (3) had poor nutritional status, (4) were immunocompromised, (5) were rheumatoid, or (6) were diabetic. In the current study, periarticular injection of a specific mixture decreased PCAMC for up to 42 hours. In 2013, Andersen et al21 advocated the addition of ketorolac during local infiltration analgesia. They prepared the medication by mixing 150 mL of ropivacaine 2 mg/mL with 1 mL of ketorolac 30 mg/mL; to 100 mL of this mixture was added 0.5 mL of epinephrine 1 mg/mL. The mixture containing epinephrine was injected into the posterior capsule and around the prosthesis, and the 50 mL without epinephrine was injected into the fascia and subcutis. An intra-articular catheter was left in place to enable eight postoperative bolus injections of analgesic without epinephrine. It was found that ketorolac successfully reduced morphine consumption, pain intensity, and length of hospital stay.21 At the AHNH, 1 mL of ketorolac 30 mg/mL has been added to IPMI since July 2014 to provide local anti-inflammatory action and enhance the analgesic effect.
 
Regional anaesthesia is the preferred method.7 8 The previous randomised trials of multimodal drug injection in TKA involved a mixed group of GA and regional anaesthesia,6 or excluded the samples of GA.13 Randomisation of anaesthesia in clinical trials is unethical because of the obvious benefit of regional anaesthesia that avoids central nervous system depression and prevents deep vein thrombosis following TKA.22 A retrospective study stratifying different types of anaesthesia is therefore the preferred method, as in the current study. The present study revealed that IPMI in TKA under NeA could significantly decrease PCAMC for 24 hours.
 
A concordant finding could not be obtained between the effect of IPMI on PCAMC and subjective pain scale. It is possible that the greater use of PCA morphine in the control group in earlier years explained the lower postoperative pain scores. Nonetheless, this could not explain the absence of this phenomenon in the GA subgroup. Rather, it may be explained by the secular change in patient expectations. To many patients early on, TKA was well-known to be associated with a high level of pain. They may have therefore used more PCA morphine. The level of perceived pain was then less than expected with a consequent lower pain score. With increasing popularity of TKA and knowledge of IPMI, patients may have been overly optimistic about the outcome. The 4-point pain scale used in the control group may have exaggerated this discrepancy when one lower grade of pain severity was equal to a 0.25-drop in pain score compared with a 0.1-drop in the 10-point pain scale.
 
Lamplot et al23 reported that the use of periarticular injection and multimodal analgesics could lower pain scores, with fewer adverse effects, lower narcotic usage, higher patient satisfaction, and faster recovery. At the AHNH, TKA protocols for perioperative pain management, blood management, and rehabilitation were altered following the establishment of the Joint Replacement Centre in October 2015. For the pain management protocol, the hospital now uses preemptive oral pregabalin, paracetamol, and etoricoxib if not contra-indicated. The anaesthetist performs a single-injection femoral nerve block or adductor canal block before anaesthesia. Surgeons deliver IPMI. The postoperative cocktail consists of pregabalin, paracetamol, etoricoxib, and tramadol. The new protocols have made a significant contribution to the improvement in postoperative patient recovery.24 25 Further studies will be conducted on the new perioperative analgesic protocol to confirm its efficacy.
 
There were limitations to this retrospective study, which compared two groups of patients with TKA performed during different periods of time. First, possible secular changes to patient expectations and pain assessment tools might have led to discordant outcomes when IPMI was evaluated. Second, the pain scale did not focus separately on rest pain and motion pain. Third, although the data were selectively verified by the author, there might have been errors in data extraction and coding of other data. Last but not least, because TKAs were performed by more than one surgeon, it was difficult to standardise the intra-operative soft-tissue tension and balancing and the injection technique of IPMI. If the knee was made too tight or IPMI missed the quadriceps tendon, the patient would experience greater postoperative pain.
 
In conclusion, IPMI effectively decreases parenteral morphine consumption for up to 42 hours following TKA in patients with OA of the knee.
 
Declaration
The author has disclosed no conflicts of interest. No funding was received for this study.
 
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9. Lozano LM, Núñez M, Sastre S, Popescu D. Total knee arthroplasty in the context of severe and morbid obesity in adults. Open Obes J 2012;4:1-10. Crossref
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11. Heard SO, Edwards WT, Ferrari D, et al. Analgesic effect of intraarticular bupivacaine or morphine after arthroscopic knee surgery: a randomized, prospective, double-blind study. Anesth Analg 1992;74:822-6. Crossref
12. Woolf CJ, Chong MS. Preemptive analgesia—treating postoperative pain by preventing the establishment of central sensitization. Anesth Analg 1993;77:362-79. Crossref
13. Mullaji A, Kanna R, Shetty GM, Chavda V, Singh DP. Efficacy of periarticular injection of bupivacaine, fentanyl, and methylprednisolone in total knee arthroplasty: a prospective, randomized trial. J Arthroplasty 2010;25:851-7. Crossref
14. Mauerhan DR, Campbell M, Miller JS, Mokris JG, Gregory A, Kiebzak GM. Intra-articular morphine and/or bupivacaine in the management of pain after total knee arthroplasty. J Arthroplasty 1997;12:546-52. Crossref
15. Stein C. The control of pain in peripheral tissue by opioids. N Engl J Med 1995;332:1685-90. Crossref
16. Stein C. Peripheral analgesic actions of opioids. J Pain Symptom Manage 1991;6:119-24. Crossref
17. Stein C. Peripheral mechanisms of opioid analgesia. Anesth Analg 1993;76:182-91. Crossref
18. Leone S, Di Cianni S, Casati A, Fanelli G. Pharmacology, toxicology, and clinical use of new long acting local anesthetics, ropivacaine and levobupivacaine. Acta Biomed 2008;79:92-105.
19. Parvataneni HK, Ranawat AS, Ranawat CS. The use of local periarticular injections in the management of postoperative pain after total hip and knee replacement: a multimodal approach. Instr Course Lect 2007;56:125-31.
20. Parvataneni HK, Shah VP, Howard H, Cole N, Ranawat AS, Ranawat CS. Controlling pain after total hip and knee arthroplasty using a multimodal protocol with local periarticular injections: a prospective randomized study. J Arthoplasty 2007;22(6 Suppl 2):33-8. Crossref
21. Andersen KV, Nikolajsen L, Haraldsted V, Odgaard A, Soballe K. Local infiltration analgesia for total knee arthroplasty: should ketorolac be added? Br J Anaesth 2013;111:242-8. Crossref
22. Sharrock NE, Haas SB, Hargett MJ, Urquhart B, Insall JN, Scuderi G. Effects of epidural anesthesia on the incidence of deep-vein thrombosis after total knee arthroplasty. J Bone Joint Surg Am 1991;73:502-6. Crossref
23. Lamplot JD, Wagner ER, Manning DW. Multimodal pain management in total knee arthroplasty: a prospective randomized controlled trial. J Arthroplasty 2014;29:329-34. Crossref
24. Ng FY, Ng JK, Chiu KY, Yan CH, Chan CW. Multimodal periarticular injection vs continuous femoral nerve block after total knee arthroplasty: a prospective, crossover, randomized clinical trial. J Arthroplasty 2012;27:1234-8. Crossref
25. Wu JW, Wong YC. Elective unilateral total knee replacement using continuous femoral nerve blockade versus conventional patient-controlled analgesia: perioperative patient management based on a multidisciplinary pathway. Hong Kong Med J 2014;20:45-51.

Bacteriology and risk factors associated with periprosthetic joint infection after primary total knee arthroplasty: retrospective study of 2543 cases

Hong Kong Med J 2018 Apr;24(2):152–7 | Epub 29 Mar 2018
DOI: 10.12809/hkmj176885
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Bacteriology and risk factors associated with periprosthetic joint infection after primary total knee arthroplasty: retrospective study of 2543 cases
KT Siu1; FY Ng2; PK Chan1; Henry CH Fu1; CH Yan3; KY Chiu3
1 Department of Orthopaedics and Traumatology, Queen Mary Hospital, Pokfulam, Hong Kong
2 Private practice, Hong Kong
3 Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong
 
Corresponding author: Prof KY Chiu (pkychiu@hkucc.hku.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Periprosthetic joint infection after total knee arthroplasty is a serious complication. This study aimed to identify risk factors and bacteriological features associated with periprosthetic joint infection after primary total knee arthroplasty performed at a teaching hospital.
 
Methods: We reviewed 2543 elective primary total knee arthroplasties performed at our institution from 1993 to 2013. Data were collected from the Hong Kong Hospital Authority’s Clinical Data Analysis and Reporting System, the Infection Control Team, and the joint replacement division registry. The association between potential risk factors and periprosthetic joint infection was examined by univariable analysis and multivariable logistic regression. Univariable analyses were also performed to examine the association between potential risk factors and bacteriology and between potential risk factors, including bacteriology, and early-onset infection.
 
Results: The incidence of periprosthetic joint infection in our series was 1.34% (n=34). The incidence of early-onset infection was 0.39% (n=24). Of the periprosthetic joint infections, 29.4% were early-onset infections. In both univariable and multivariable analyses, only rheumatoid arthritis was a significant predictor of periprosthetic joint infection. Methicillin-sensitive Staphylococcus aureus was the most common causative organism. We did not identify any significant association between potential risk factors and bacteriology. Periprosthetic joint infection caused by skin flora was positively associated with early-onset infection but the association was not statistically significant.
 
Conclusion: The incidence of periprosthetic joint infection after elective primary total knee arthroplasty performed at our institution from 1993 to 2013 was 1.34%. Rheumatoid arthritis was a significant risk factor for periprosthetic joint infection.
 
 
New knowledge added by this study
  • The incidence of periprosthetic joint infection after elective primary total knee arthroplasty performed at our institution from 1993 to 2013 was 1.34%.
  • Rheumatoid arthritis was the only significant risk factor identified in the series.
Implications for clinical practice or policy
  • Early-onset infection may be associated with infection with skin flora. Therefore, in early-onset periprosthetic joint infection with negative cultures, an empirical antibiotic regimen should preferably provide adequate coverage against skin flora organisms.
 
 
Introduction
Periprosthetic joint infection (PJI) is an uncommon but serious complication after total knee arthroplasty (TKA). Treatment is often challenging and has a major impact on the patient. Multiple operations are often required and patients may suffer from a long period of disability. Moreover, PJI incurs considerable health care costs.1 2 3 Therefore, multiple strategies including antibiotic prophylaxis, body exhaust systems, and laminar airflow systems have been developed to reduce the incidence of PJI. Studies have also identified modifiable risk factors for PJI after elective total joint replacement,4 5 6 7 8 9 10 11 12 13 14 with the aim of further reducing the incidence of PJI. However, local data on the risk factors and bacteriological features associated with PJI are still lacking.
 
This study had several aims. First, it aimed to provide the most up-to-date local data on incidence of and risk factors for PJI, including age, sex, presence of diabetes, presence of rheumatoid arthritis, and one-stage bilateral TKA. Second, this study aimed to provide an update on the bacteriology of PJI after elective primary TKA and to examine the association between potential risk factors and bacteriology. Third, we attempted to determine which risk factors, including bacteriology, were more likely to be associated with early-onset infection after elective primary TKA.
 
It is hoped that risk factors can be optimised or modified to prevent infection after TKA. Furthermore, an improved understanding of local bacteriological patterns and their relationship with various risk factors can help guide antimicrobial therapy.
 
Methods
We reviewed 2543 elective primary TKAs performed at the Queen Mary Hospital, Hong Kong, from 1993 to 2013. Data were collected by an infection control nurse of the Department of Microbiology who was blinded to the study objectives. The cohort data were collected from the Hong Kong Hospital Authority’s Clinical Data Analysis and Reporting System, the Infection Control Team, and the hospital’s joint replacement division registry. The keywords used in the data search were ‘periprosthetic joint infection’, ‘total knee arthroplasty’, and ‘surgical site infection’. Revision arthroplasties and knee arthroplasties for malignant conditions were excluded from the study. In patients with a history of native joint infection, elective primary TKA was performed only after eradication of the infection. Patients with active bacteraemia were also precluded from elective primary TKA until they were infection-free. There were no cases of severe immunosuppression. In relation to infection control, the majority of perioperative protocols for primary TKA were the same throughout the study period. Preoperatively, intravenous antibiotic prophylaxis (1 g of cefazolin) was given within 1 h before skin incision. In patients with penicillin allergy, other antibiotics were prescribed as appropriate. Intra-operatively, laminar airflow and body exhaust systems were used. There was no routine use of antibiotic-loaded cement or postoperative antibiotics. Postoperative wound management was the same throughout the study period.
 
Cohort characteristics, occurrence of PJI, and bacteriological data were retrieved. Bacterial type was defined as infection with skin flora or non-skin flora. Skin flora included methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S aureus (MRSA), methicillin-susceptible coagulase-negative staphylococci (MSCNS), and methicillin-resistant coagulase-negative staphylococci (MRCNS). Other organisms were considered non-skin flora.
 
The following potential risk factors for PJI were analysed: age, sex, presence of diabetes, presence of rheumatoid arthritis, and one-stage bilateral TKA. They were examined by univariable analyses and then multivariable logistic regression to identify potential predictors of PJI, while controlling for confounders. We also studied the association of those potential risk factors with bacteriology and with the timing of infection onset; culture-negative PJI was excluded from these analyses. According to a working party convened by the Musculoskeletal Infection Society in 2014,15 PJI that occurs within 90 days of the index operation is considered early-onset infection, whereas PJI that occurs later is considered late-onset infection.
 
Both univariable and multivariable logistic regression in this study used the simultaneous entry method, with covariates of age (as a continuous variable) and sex, diabetes, rheumatoid arthritis, and one-stage bilateral TKA (as dichotomous variables). Outcomes are presented as odds ratios (ORs) with 95% confidence intervals (CIs). The regression model and data fitting were assessed using the Hosmer–Lemeshow goodness-of-fit test, and diabetes and one-stage bilateral TKA were excluded from the final model because of poor goodness-of-fit. For associations between potential risk factors and bacteriology and between potential risk factors and early onset of infection, only univariable analyses were used owing to small numbers of events. Categorical variables were compared with the chi-square test, whereas age was compared with the independent t test (two-tailed). Significance was assumed if P<0.05. All statistical analyses were conducted using SPSS version 22.0 (IBM Corporation, Armonk [NY], United States). The study was conducted in accordance with the principles outlined in the Declaration of Helsinki.
 
Results
The incidence of PJI in our series was 1.34% (n=34). The incidence of early-onset infection was 0.39% (n=10) and that of late-onset infection was 0.94% (n=24). Among the cases PJI, 29.4% were early-onset infection. Early-onset infection occurred within a median of 17 days after arthroplasty (interquartile range, 9-32 days). Late-onset infection occurred within a median of 1 year and 8 months after arthroplasty (interquartile range, 7 months to 2 years and 11 months). Fifty-nine percent of infections occurred in the first year of surgery, whereas 74% occurred in the first 2 years.
 
The mean (standard deviation) age was 69 (9) years, with a range from 21 to 91 years; age followed a normal distribution. Overall, PJI developed in 10 males (1.9%) and 24 females (1.2%). In the one-stage bilateral TKA group, PJI occurred in 13 knees (1.2%). For the single-side TKA group, 21 knees (1.4%) developed PJI. Nine patients with diabetes (1.9%) and 25 patients without diabetes (1.2%) developed PJI. The highest rate of PJI, at 3.1%, was found in patients with rheumatoid arthritis, compared with 1.2% in patients without rheumatoid arthritis. The descriptive data are summarised in Table 1.
 

Table 1. Descriptive statistics for potential risk factors according to occurrence of periprosthetic joint infection after primary total knee arthroplasty
 
The most frequent causative organism was MSSA (26.5%, n=9), followed by MRSA (17.6%, n=6), Streptococcus spp (8.8%, n=3), MSCNS (5.9%, n=2), Escherichia coli (5.9%, n=2), Salmonella (5.9%, n=2), MRCNS (2.9%, n=1) and Mycobacterium tuberculosis (2.9%, n=1), The three cases of streptococcal infection comprised two Streptococcus dysgalactiae infections and one Streptococcus agalactiae infection. Culture-negative PJI comprised 23.5% of cases (n=8). Methicillin-resistant strains constituted 39% of all staphylococcal organisms. There was no significant association between the potential risk factors and skin flora infection (Table 2).
 

Table 2. Association between potential risk factors for periprosthetic joint infection after primary total knee arthroplasty and bacteriology
 
Rheumatoid arthritis was a significant risk factor of PJI in the univariable analysis, with an OR of 2.67 (95% CI, 1.15-6.20; P=0.02), as well as in the multivariable analysis, with an OR of 3.12 (CI, 1.29-7.56; P=0.01) [Table 3]. Being male (OR=1.9; P=0.11 in the multivariable analysis) and having diabetes (OR=1.54; P=0.27 in the univariable analysis) were not significantly associated with PJI.
 

Table 3. Results of univariable and multivariable analyses of potential risk factors for periprosthetic joint infection after primary total knee arthroplasty
 
Age (P=0.655), sex (P=0.961), diabetes (P=0.462), and rheumatoid arthritis (P=0.315) were not associated with early-onset infection (Table 4). Infection caused by skin flora was associated with early-onset infection (P=0.099), but the association was not statistically significant.
 

Table 4. Association between potential risk factors for periprosthetic joint infection after primary total knee arthroplasty and onset of infection
 
Discussion
In this study, the incidence of PJI after primary TKA was 1.34% and the incidence of early-onset infection was 0.39%. The majority of PJIs (70%) were late-onset infections. The reported incidence of PJI after primary TKA ranges from 1.1% to 2.18%.16 17 18 Pulido et al16 reported the incidence of PJI after TKA to be 1.1%, of which 27% were diagnosed during the first 30 days after arthroplasty, and a majority of 65% were diagnosed in the first year after surgery. In our study, the average time to diagnosis was 431 days after the index surgery (range, 11-1699 days).
 
Rheumatoid arthritis was a significant risk factor for PJI after primary TKA. This finding is in keeping with the current literature.6 8 11 Although various authors have found male sex to be a risk factor for PJI,4 19 20 the association was not significant in this study. The OR of 1.9 may be of clinical importance but not significant as a result of the small number of PJIs and inadequate statistical power. The correlation between age and PJI has been a matter of controversy, with some reports mentioning young age as a risk factor for PJI4 21 and some otherwise.22 In our study, age was not associated with PJI occurrence. For one-stage bilateral TKA, age has been a controversial risk factor for PJI. Some studies16 23 have suggested that one-stage bilateral TKA is associated with an increased risk of superficial and deep infection. Hussain et al24 nonetheless reported a similar infection rate between one- and two-stage bilateral TKA. Our study did not find an association between one-stage bilateral TKA and PJI occurrence.
 
The local bacteriological pattern for PJI was comparable to that reported in the literature.4 16 In our study, skin flora and gram-positive bacteria were the most commonly isolated organisms, followed by gram-negative bacteria such as Escherichia coli and Salmonella. Coagulase-negative staphylococci were the most common causative organism in one study.4 In contrast, in our series, S aureus was the most common causative organism, particularly methicillin-sensitive strains. Methicillin-resistant strains were less common in our series, constituting 39% of all staphylococcal organisms.
 
Other authors have reported that male sex is a risk factor for PJI, which may be related to a sex difference in immune response to pathogenic bacteria. Studies6 have shown that males (compared with females) have a significantly higher likelihood of being a persistent S aureus carrier. However, our study did not support male sex as a risk factor for infection with skin flora. With regard to onset of infection, PJI caused by skin flora was positively associated with early-onset infection, although the association did not reach statistical significance (P=0.099). Direct inoculation and spread from contiguous foci of infection are more common in early-onset infection caused by wound complications and local soft-tissue conditions. In contrast, distant foci of infection, such as in bacteraemia, play a more important role in late-onset infection. Therefore, in early-onset periprosthetic joint infection with negative cultures, an empirical antibiotic regimen may provide adequate coverage against skin flora organisms.
 
Fan et al20 reported 479 TKAs and rates of 1.9% for superficial wound infection, 0.2% for early deep infection (n=1), and 0.6% for late deep infection (n=2). Methicillin-sensitive S aureus and coagulase-negative staphylococci were causative organisms. Lee et al25 reviewed 1133 primary TKAs and found a 0.71% incidence of PJI. The most common causative organisms in descending order were methicillin-sensitive S aureus, coagulase-negative staphylococci, methicillin-resistant S aureus, and Pseudomonas aeruginosa. This finding is in keeping with our data. Among risk factors identified by Lee et al25 were young age, diabetes, anaemia, thyroid disease, heart disease, lung disease, and long operating time. However, the researchers identified limitations of having only a small number of patients with infection (n=8) and insufficient power for analysis. In addition, multivariable analysis should have been performed to account for the effect of confounders among the multiple risk factors. They also reported the limitation that the mean follow-up duration was only 2 years. A short follow-up period may underestimate the occurrence of late-onset infection.
 
Our study has several limitations. The number of PJI-positive cases was small and thus subgroup analysis was limited. This study included subjects treated at a single centre in Hong Kong; multicentre studies may improve the representativeness of local data. In addition, perioperative management for elective TKA has evolved over the past 20 years, including the introduction of an MRSA-screening programme in 2011. In the screening programme, a nasal swab is taken from all elective joint-replacement patients. Patients with a positive result are prescribed 5 days of decolonisation therapy including a daily chlorhexidine bath. Furthermore, intravenous vancomycin is now administered for prophylaxis instead of cefazolin.26
 
There are many potential risk factors for PJI documented in the literature. Nonetheless, only a limited number were included in this study, most of which are not be modifiable. Thus, it may not provide the necessary guidance for preoperative optimisation. Furthermore, the exclusion of some potential risk factors may have led to inadequate control for potential confounding factors. Inclusion of more risk factors with better characterisation is needed to provide a more comprehensive understanding and to better account for the confounding effect of other variables.
 
Conclusion
The incidence of PJI after elective primary TKA in our institution over two decades from 1993 to 2013 was 1.34%. Rheumatoid arthritis was a significant risk factor for PJI in this series. In the early-onset infection group, PJI was caused by skin flora, but this was not statistically significant. It is hoped that this study has updated the local data for PJI after primary TKA and serves as a model for future related studies.
 
Acknowledgements
We thank colleagues from the Department of Orthopaedics and Traumatology and the Infection Control Team at the Queen Mary Hospital for their assistance in data collection, and those who advised on this project to make its publication possible.
 
Declaration
The authors have no conflicts of interest to disclose.
 
References
1. Kurtz SM, Lau E, Watson H, Schmier JK, Parvizi J. Economic burden of periprosthetic joint infection in the United States. J Arthroplasty 2012;27(8 Suppl):61-5.e1. Crossref
2. Lamarsalle L, Hunt B, Schauf M, Szwarcensztein K, Valentine WJ. Evaluating the clinical and economic burden of healthcare-associated infections during hospitalization for surgery in France. Epidemiol Infect 2013;141:2473-82. Crossref
3. Nero DC, Lipp MJ, Callahan MA. The financial impact of hospital-acquired conditions. J Health Care Finance 2012;38:40-9.
4. Crowe B, Payne A, Evangelista PJ, et al. Risk factors for infection following total knee arthroplasty: a series of 3836 cases from one institution. J Arthroplasty 2015;30:2275-8. Crossref
5. Meller MM, Toossi N, Johanson NA, Gonzalez MH, Son MS, Lau EC. Risk and cost of 90-day complications in morbidly and superobese patients after total knee arthroplasty. J Arthroplasty 2016;31:2091-8. Crossref
6. Zmistowski B, Alijanipour P. Risk factors for periprosthetic joint infection. In: Springer BD, Parvizi J, editors. Periprosthetic Joint Infection of the Hip and Knee. New York: Springer; 2014: 15-40. Crossref
7. Jämsen E, Huhtala H, Puolakka T, Moilanen T. Risk factors for infection after knee arthroplasty. A register-based analysis of 43,149 cases. J Bone Joint Surg Am 2009;91:38-47. Crossref
8. Wilson MG, Kelley K, Thornhill TS. Infection as a complication of total knee-replacement arthroplasty. Risk factors and treatment in sixty-seven cases. J Bone Joint Surg Am 1990;72:878-83. Crossref
9. Namba RS, Inacio MC, Paxton EW. Risk factors associated with deep surgical site infections after primary total knee arthroplasty: an analysis of 56,216 knees. J Bone Joint Surg Am 2013;95:775-82. Crossref
10. Pruzansky JS, Bronson MJ, Grelsamer RP, Strauss E, Moucha CS. Prevalence of modifiable surgical site infection risk factors in hip and knee joint arthroplasty patients at an urban academic hospital. J Arthroplasty 2014;29:272-6. Crossref
11. Chesney D, Sales J, Elton R, Brenkel IJ. Infection after knee arthroplasty: a prospective study of 1509 cases. J Arthroplasty 2008;23:355-9. Crossref
12. Moucha CS, Clyburn T, Evans RP, Prokuski L. Modifiable risk factors for surgical site infection. J Bone Joint Surg Am 2011;93:398-404.
13. Peersman G, Laskin R, Davis J, Peterson M. Infection in total knee replacement: a retrospective review of 6489 total knee replacements. Clin Orthop Relat Res 2001;392:15-23. Crossref
14. Rasouli MR, Restrepo C, Maltenfort MG, Purtill JJ, Parvizi J. Risk factors for surgical site infection following total joint arthroplasty. J Bone Joint Surg Am 2014;96:e158. Crossref
15. Parvizi J, Gehrke T; International Consensus Group on Periprosthetic Joint Infection. Definition of periprosthetic joint infection. J Arthroplasty 2014;29:1331. Crossref
16. Pulido L, Ghanem E, Joshi A, Purtill JJ, Parvizi J. Periprosthetic joint infection: the incidence, timing, and predisposing factors. Clin Orthop Relat Res 2008;466:1710-5. Crossref
17. Tsaras G, Osmon DR, Mabry T, et al. Incidence, secular trends, and outcomes of prosthetic joint infection: a population based study, Olmsted County, Minnesota, 1969-2007. Infect Control Hosp Epidemiol 2012;33:1207-12. Crossref
18. Tande AJ, Patel R. Prosthetic joint infection. Clin Microbiol Rev 2014;27:302-45. Crossref
19. Herwaldt LA, Cullen JJ, French P, et al. Preoperative risk factors for nasal carriage of Staphylococcus aureus. Infect Control Hosp Epidemiol 2004;25:481-4. Crossref
20. Fan JC, Hung HH, Fung KY. Infection in primary total knee replacement. Hong Kong Med J 2008;14:40-5.
21. Meehan JP, Danielsen B, Kim SH, Jamali AA, White RH. Younger age is associated with a higher risk of early periprosthetic joint infection and aseptic mechanical failure after total knee arthroplasty. J Bone Joint Surg Am 2014;96:529-35. Crossref
22. Berbari EF, Osmon DR, Lahr B, et al. The Mayo prosthetic joint infection risk score: implication for surgical site infection reporting and risk stratification. Infect Control Hosp Epidemiol 2012;33:774-81. Crossref
23. Luscombe JC, Theivendran K, Abudu A, Carter SR. The relative safety of one-stage bilateral total knee arthroplasty. Int Orthop 2009;33:101-4. Crossref
24. Hussain N, Chien T, Hussain F, et al. Simultaneous versus staged bilateral total knee arthroplasty: a meta-analysis evaluating mortality, peri-operative complications and infection rates. HSS J 2013;9:50-9. Crossref
25. Lee QJ, Mak WP, Wong YC. Risk factors for periprosthetic joint infection in total knee arthroplasty. J Orthop Surg (Hong Kong) 2015;23:282-6. Crossref
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Endobronchial valve for treatment of persistent air leak complicating spontaneous pneumothorax

Hong Kong Med J 2018 Apr;24(2):158–65 | Epub 4 Apr 2018
DOI: 10.12809/hkmj176823
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Endobronchial valve for treatment of persistent air leak complicating spontaneous pneumothorax
WC Yu, MB, BS, FHKCP1; Ellen LM Yu, MSc2; HC Kwok, MB, BS, FHKCP1; HL She, MB, BS, FRCR3; KK Kwong, MB, BS, FHKCP1; YH Chan, MB, BS, FHKCP1; YL Tsang, BSc4; YC Yeung, MB, BS, FHKCP1
1 Department of Medicine and Geriatrics, Princess Margaret Hospital, Laichikok, Hong Kong
2 Clinical Research Centre, Princess Margaret Hospital, Laichikok, Hong Kong
3 Department of Radiology, Princess Margaret Hospital, Laichikok, Hong Kong
4 Central Endoscopy Unit, Princess Margaret Hospital, Laichikok, Hong Kong
 
Corresponding author: Dr WC Yu (h7537800@connect.hku.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Endobronchial one-way valves have been proposed as treatment for persistent air leak complicating spontaneous pneumothorax in which surgical intervention is not feasible. However, published data on efficacy, safety, and factors associated with success are scanty.
 
Methods: This is a retrospective study of 37 patients at a general hospital from 2008 to 2016. The impact of endobronchial valve implantation on the time to air-leak cessation after bronchoscopy was evaluated.
 
Results: The median patient age was 71 years. The majority of patients were males (92%), were ever-smokers (83%), had at least one co-morbidity (97%), and had secondary spontaneous pneumothorax (89%). Nineteen patients (51%) had a mean of 2.6 endobronchial valves implanted (range, 1-6). The air leak ceased within 72 hours for only eight patients (22% of the complete cohort), with immediate air-leak cessation after completion of endobronchial valve implantation. All six successful cases that had computed tomographic data of the thorax were shown to have bilateral intact interlobar fissures. The median (interquartile range) Charlson co-morbidity index was 1 (0.25-1) and 2 (1-3) for the success group and failure group, respectively (P=0.029). All patients in the no-endobronchial valve group survived, whereas three patients in the endobronchial valve group died within 30 days of endobronchial valve implantation.
 
Conclusion: Only a small proportion of cases of endobronchial valve implantation for air leak complicating pneumothorax had unequivocal success. Intact bilateral interlobar fissures appear to be a necessary, though not sufficient, condition for success. Patients with fewer medical co-morbidities and immediate air-leak cessation after endobronchial valve implantation have a higher likelihood of success.
 
 
New knowledge added by this study
  • Only a small proportion of cases (22%) of persistent air leak complicating spontaneous pneumothorax can be successfully treated by endobronchial valve (EBV).
  • Cases in which the air leak does not cease immediately after completion of EBV implantation are likely to fail.
  • Patients with any non-intact interlobar fissures are likely to experience treatment failure.
Implications for clinical practice or policy
  • EBV treatment may be attempted in patients with persistent air leak complicating spontaneous pneumothorax who are not candidates for surgery, have intact interlobar fissures, and do not have severe medical comorbidities.
  • Plain computed tomography of the thorax should be performed to routinely assess patients who are candidates for EBV treatment.
  • Cases of completed EBV implantation that still have an air leak may have the EBVs removed.
 
 
Introduction
Persistent air leak is a common complication of spontaneous pneumothorax being treated by chest tube drainage. In one report, the median time for spontaneous cessation of air leak was 7 days for primary spontaneous pneumothorax and 11 days for secondary spontaneous pneumothorax.1 In another report, 75% and 100% of cases of primary spontaneous pneumothorax resolved by 7 days and 14 days, respectively, whereas the corresponding proportions for secondary spontaneous pneumothorax were 61% and 79%, respectively.2 It is generally recommended that surgical intervention be considered when an air leak continues for 7 to 14 days after chest tube insertion. Unfortunately, some patients are poor candidates for surgery, and some patients may refuse surgery. Prolonged chest tube in situ, however, is undesirable because of an increased risk of complications, prolonged immobilisation and its consequences, and increased duration of hospital stay. Alternative means to shorten the duration of air leakage are thus needed.
 
Endobronchial one-way valves (EBVs) have been used to treat persistent air leak complicating pneumothorax. The rationale is that air leakage will stop if air is prevented from entering the airway leading to the leak site. Preliminary case reports showed encouraging results.3 4 5 6 7 8 9 10 11 12 13 14 Larger case series showed similarly favourable results.15 16 17 18 19 20 21 22 23 However, most of these reports include a mix of post-surgical pneumothoraces, spontaneous pneumothoraces, and other aetiologies. Moreover, there is scanty information on overall efficacy, short-term safety, and factors related to favourable clinical outcomes.
 
The Princess Margaret Hospital, an acute-care general hospital in Hong Kong, has been using EBV for persistent air leak complicating pneumothorax on compassionate grounds since 2008, and its preliminary experience on three apparently successful cases was reported in 2009.11 However, it was subsequently found that in many cases, the leak site could not be identified, so EBV could not be deployed. In some other cases, despite leak site identification and EBV deployment, the air leak may not resolve completely, or it may recur after a few hours. We therefore hypothesise that EBV treatment has a low success rate in real-life situations. To test this hypothesis, we retrospectively compared the clinical course of patients with and without EBV use for persistent air leak complicating spontaneous pneumothorax during an 8-year period at a single centre.
 
Methods
Patients
This retrospective chart review was based on patients who were managed at the Princess Margaret Hospital from May 2008 to April 2016. Eligible patients were those with spontaneous pneumothorax who were undergoing chest tube drainage and who had had an air leak lasting more than 1 week. All showed bubbling in the drainage bottle during both expiration and inspiration, with water suction at -20 cm. Patients either refused surgery or were considered by the thoracic surgeon to be unsuitable for surgical intervention owing to advanced age, poor lung function, major medical co-morbidities, or a combination of these.
 
Intervention
Bronchoscopy with the intention of EBV implantation to stop the air leak was suggested to eligible patients. Some were reluctant at first but consented after further days of air leakage. Procedures for identifying the leak site and deploying EBV were as described previously.11 Briefly, an endobronchial inflatable balloon was used to occlude lobar or segmental bronchi sequentially. If bubbling from the chest drainage bottle stopped, or was greatly reduced, then the lobe or segment was selected for endobronchial valve implantation. The Zephyr EBV (Emphasys Inc, now Pulmonx Inc, Redwood City [CA], United States) was used throughout. Patients were observed closely for continued air leak after bronchoscopy. Chest tubes were removed as soon as possible after air-leak cessation, typically within 1 or 2 days, as is usual clinical practice.
 
Data collection and outcome measures
Data on demographic and disease characteristics, details of bronchoscopy, and survival after bronchoscopy were recorded. Spirometry data were analysed if available within 1 year of bronchoscopy. Spirometry was performed according to the American Thoracic Society / European Respiratory Society criteria24 and using reference values for Hong Kong adults.25 No spirometry was performed during the period of chest tube drainage or with EBV in situ. Computed tomography images, if available, were viewed in axial, sagittal, and coronal planes by a single radiologist who was blinded to other study data. The integrity of the fissures was defined as more than 90% completeness on at least one axis.26 Outcome measures included whether EBV was implanted, time to air-leak cessation, and 30-day all-cause mortality after bronchoscopy.
 
Definition of therapeutic success
Therapeutic success was defined as cessation of the air leak within 72 hours of EBV implantation. Cases with EBV implanted but with the air leak lasting more than 72 hours afterwards, cessation of air leak within 72 hours of bronchoscopy owing to other interventions (such as surgery), cases without EBV implantation, and cases of chest tube removal while the air leak persisted (such as following unintended displacement) were considered cases of failure.
 
Statistical analysis
The Mann-Whitney U test and Fisher’s exact test were used to examine differences between groups. The Kaplan-Meier log-rank test and Gehan-Breslow-Wilcoxon test were used to analyse time to air-leak cessation after first bronchoscopy among patients with and without EBV implantation. The association between EBV implantation and air-leak cessation was assessed in a multivariable Cox proportional hazards regression model that was adjusted for ‘days on chest tube before first bronchoscopy’ and factors with P<0.2 in univariable regression analyses. The accuracy, sensitivity, specificity, and positive and negative predictive values of using the presence of an intact interlobar fissure as an indicator of a successful outcome were calculated. Statistical analyses were performed using SPSS 22.0 for Windows (IBM Corp., Armonk [NY], United States) and OpenEpi: Open Source Epidemiologic Statistics for Public Health, version 3.01 (http://www.openepi.com). Statistical significance was set at P<0.05.
 
This study was approved by the Research Ethics Committee of the Kowloon West Cluster of the Hong Kong Hospital Authority, with the requirement for patient consent waived. This report conforms to the STROBE 2008 guidelines.27
 
Results
Baseline characteristics
During the study period, 38 patients underwent bronchoscopy for persistent air leak complicating spontaneous pneumothorax at our institution. One patient was excluded because the air leak was subsequently found to result from the chest tube having been inserted into an airway. Of the remaining 37 patients, 35 were assessed by the surgeon and considered unfit for surgery, and two patients with primary spontaneous pneumothorax refused surgery. The median patient age was 71 years and most (34; 92%) were males. The majority (83%) were ever-smokers. All but one (97%) had at least one co-morbidity and the median Charlson co-morbidity index was 1. Fifteen patients (41%) had a left pneumothorax. Thirty-three (89%) had secondary spontaneous pneumothorax, of which 23 had chronic obstructive pulmonary disease with or without other lung diseases. Of the 22 secondary spontaneous pneumothorax cases with spirometric data, the median forced expiratory volume in 1 second (FEV1) was 0.94 L; median percentage of predicted FEV1 was 43.5%; and median FEV1 to forced vital capacity ratio was 0.45. Eleven patients (30%) had at least one attempt at talc pleurodesis before bronchoscopy. The median number of days off chest tube use before bronchoscopy was 25 (Table 1).
 

Table 1. Baseline characteristics of patients with and without endobronchial valve implantation at first bronchosopy
 
Endobronchial one-way valve implantation and time to air-leak cessation
Nineteen patients (51%) had a mean of 2.6 EBVs implanted (range, 1-6). The sites of EBV implantation were as follows: 11 in the right upper lobe, one in the right middle lobe, none in the right lower lobe, five in the left upper lobe, and two in the left lower lobe. Of the 18 patients without an EBV implanted, the target site for EBV implantation could not be identified in 17. In the remaining patient, despite identification of the air leak in the left upper lobe, EBV implantation was followed by severe oxygen desaturation and had to be abandoned.
 
There were eight successful cases among patients with EBVs implanted. Among these, seven patients had immediate and lasting cessation of the air leak, and the chest tube was removed within 2 days. One patient had immediate air-leak cessation but there was recurrence after 2 hours. The air leak subsided completely within 72 hours, and the chest tube was removed on day 4. Among the 11 cases of failure after EBV implantation, the air leak stopped immediately in three cases but recurred soon after and persisted beyond 72 hours. In the other eight cases, the air leak was reduced temporarily but was present beyond 72 hours. In the group without an implanted EBV, the earliest time for air-leak cessation was day 5, and the chest tube was removed on day 8. In a Kaplan-Meier comparison of the EBV and no-EBV groups in the number of days from first bronchoscopy to air-leak cessation, the EBV group did better in the first 30 days, but the no-EBV group caught up by day 45. There was a statistically significant difference between the two groups according to the Gehan-Breslow-Wilcoxon test (P=0.027), but not the log-rank test (P=0.138) [Fig Part a]. When the same comparison was done with the eight successful cases removed from the EBV group, the two curves overlapped throughout and there was no statistically significant difference between the two groups (P=0.881 by Gehan-Breslow-Wilcoxon test and P=0.976 by log-rank test) [Fig Part b].
 

Figure. Kaplan-Meier curves of air-leak cessation after first bronchoscopy in patients with and without an implanted endobronchial valve (EBV): (a) complete cohort; (b) all eight successful cases removed from the EBV implanted group
 
In a comparison of demographic and clinical characteristics between the EBV group and the no-EBV group, the former had a significantly poorer FEV1, but not percentage of predicted FEV1. This group also had the chest tube in place for a significantly longer duration before bronchoscopy (Table 1).
 
Factors associated with a successful outcome
We further examined factors related to air-leak cessation after first bronchoscopy by Cox proportional hazards regression analysis. The implantation of an EBV was significantly associated with air-leak cessation (adjusted hazard ratio=2.39, 95% CI=1.13-5.05; P=0.023), whereas the Charlson co-morbidity index was significantly associated with delayed air-leak cessation (adjusted hazard ratio=0.78, 95% CI=0.63-0.97; P=0.026). The number of days of chest tube use before first bronchoscopy was not associated with air-leak cessation (Table 2).
 

Table 2. Cox proportional hazards regression results for air-leak cessation after first bronchoscopy
 
When comparing the eight successful cases with the 11 failed cases among those with implanted EBVs, we found no difference in any of the demographic or disease variables between the two groups, apart from the Charlson co-morbidity index, which was significantly lower for the success group (Table 3). Additionally, all eight patients (100%) in the success group had air-leak cessation immediately after EBV implantation, versus only three of 11 (27%) in the failure group (P=0.003). When we compared the eight successful cases with all 29 failed cases, again the median (interquartile range) Charlson co-morbidity index was significantly lower for the success group: 1 (0.25-1) vs 2 (1-3) [P=0.029]. This group also had significantly poorer FEV1, but not in percentage of predicted FEV1, and showed a trend towards more severe airflow obstruction, although this did not reach statistical significance (Table 3).
 

Table 3. Comparison between cases of success and failure
 
Twenty-three patients had thoracic computed tomography performed to examine the integrity of interlobar fissures. For the 13 patients with all fissures intact, six had an EBV implanted and were classed as successful cases, four had EBV implanted but were classed as failed cases, and three did not have an EBV implanted. There were five patients each in the group with any non-intact ipsilateral fissure and in the group with any non-intact contralateral fissure. Both groups had two patients with an implanted EBV and three without, and all experienced treatment failure.
 
When using the presence of all intact fissure(s) to screen for successful EBV treatment among the 23 patients who had undergone thoracic computed tomography, the accuracy was 69.6%, the sensitivity and negative predictive value were both 100%, and the specificity and positive predictive value were 58.8% and 46.2%, respectively (Table 4). When the criterion for success was immediate air-leak cessation after EBV implantation, the accuracy among the 19 patients with an implanted EBV was 84.2%, the sensitivity and negative predictive value remained at 100%, and both the specificity and positive predictive value were 72.7% (Table 4).
 

Table 4. Prediction of successful outcome by fissure integrity and air-leak cessation after endobronchial valve implantation
 
Adverse events and mortality
There was no incident of valve displacement, bleeding, or post-obstructive pneumonia. Three patients died within 30 days of EBV implantation and all had advanced age and multiple co-morbidities (Table 5). In two patients, the causes of death were clearly related to ongoing pre-existing disease. One patient had a sudden cardiac arrest on day 29 after being successfully treated with EBV, although the relationship of death to EBV was uncertain. The earliest death in the no-EBV group occurred on day 43 after bronchoscopy and the cause of death was lung cancer.
 

Table 5. Characteristics of patients with endobronchial valve implantation who died within 30 days of bronchoscopy
 
Subsequent treatments
Three patients underwent a second bronchoscopy after the first one failed, with one success and two failures. Sixteen patients received talc pleurodesis (median, 2 times; range, 1-5 times). One young patient with primary spontaneous pneumothorax underwent surgery 2 days after failed identification of the leak site by bronchoscopy. Seventeen patients did not receive any further treatment, mostly owing to early air-leak cessation.
 
Implant removal
Thirteen patients had their implanted EBVs removed after a median of 43 days (range, 21-155 days). For the remaining six patients, three died within 30 days before EBV removal was considered. Another patient had a second bronchoscopy with an additional EBV implanted but died within 30 days of the second bronchoscopy. The fifth patient had advanced lung cancer and removal of EBV was deemed unnecessary; she died 9 months after bronchoscopy. The sixth patient had severe chronic obstructive pulmonary disease and there was subjective improvement of respiratory and health status after EBV implantation, so it was decided that the EBV should remain in situ indefinitely.
 
Discussion
We have reported the first real-life cohort study that consisted entirely of spontaneous pneumothorax cases with persistent air leak treated with EBV. Our results confirm those of previous reports that EBV can be useful in hastening air-leak cessation in patients with this condition. Nonetheless, it also highlights the fact that failures are common. A site for EBV implantation was not identified in nearly half of the patients. For the 19 patients with an EBV implanted, only eight (42%) had a clear success. The overall success rate was thus only 22%.
 
In this retrospective study, we attempted to assess the efficacy of EBV treatment by comparing those who had an EBV implanted with those in whom EBV implantation was denied owing to inability to identify an implantation site or lung function that was too poor. This design is obviously inferior to a prospective randomised design. Nevertheless, the two study groups had a similar number of patients who were similar in many demographic and disease aspects. The Kaplan-Meier comparison suggested that EBV treatment is efficacious in hastening air-leak cessation. The significantly longer duration of air leakage before first bronchoscopy for the EBV group is a potential confounder, because the longer the air leak exists, the higher the probability that spontaneous resolution will occur. Nonetheless, the Cox hazards regression analysis suggested that it was not a significant factor. This finding also lends further support to the efficacy of EBV implantation in enabling early air-leak cessation.
 
A definition of success for using EBV implantation to treat persistent air leak complicating pneumothorax is difficult to formulate and has seldom been discussed in previous studies. Our criteria of cessation of air leak within 72 hours was arbitrary but is supported by our observation that patients who did not meet the criteria behaved almost exactly as if no EBV was implanted. This finding suggests that for cases in which EBV is implanted but fails, other forms of treatment should be sought early.
 
One interesting finding is that higher co-morbidity burden seemed to be a risk factor for delayed air-leak cessation, irrespective of EBV implantation status. Delayed cessation of air leak may be translated as delayed healing of the lesion responsible for the air leak, which is expected in patients with more co-morbidities and who are thus usually sicker. Nonetheless, our study was not designed to examine this association, and a properly designed study would be needed to provide definitive answers.
 
It has been widely accepted that fissure completeness of the target lobe is strongly correlated with significant lobar collapse after implantation of EBVs for volume reduction in severe pulmonary emphysema.28 29 The same is probably true for EBV treatment of persistent air leak complicating pneumothorax, although as far as we are aware there are no published data on this. Not surprisingly, our results showed that intact interlobar fissures were a necessary, but not sufficient, condition for a successful outcome. However, an interesting and unexpected finding is that patients with a non-intact fissure in the contralateral lung, but intact fissure in the ipsilateral lung, behaved similarly to those with a non-intact fissure in the ipsilateral lung. We have no explanation for this, and these findings need to be confirmed with larger studies.
 
Immediate cessation of air leak after completion of EBV implantation was strongly predictive of a successful outcome. Importantly, all eight patients with an implanted EBV and without immediate cessation of air leak failed to respond to treatment. In such cases, the EBV should have been removed immediately to save costs and to avert possible adverse events associated with EBVs. A further implication is that stringent balloon testing of cessation of air leak should be performed and, in the presence of any uncertainty, EBVs should not be implanted.
 
In all our patients, we encountered no adverse events directly attributable to EBVs. Nonetheless, the three early deaths within 30 days of EBV implantation is worrying. The causes of death in two cases were clearly the severe pre-existing illness, but the possibility that recent EBV implantation hastened the terminal event cannot be excluded. The case of sudden cardiac death raises suspicion that the implanted EBV was implicated. More data are needed to determine whether EBV implantation is associated with increased early mortality.
 
There were several limitations to our study. First, it was a retrospective one, so some data were unavailable. Second, it was not a randomised controlled study. Third, it was a single-centre study, making the data less generalisable to a wider setting. Still, single-centre retrospective case series do have the advantage that practices are more uniform and results easier to interpret. Fourth, our case series was small, making it difficult to identify definitive factors associated with clinical outcomes. Fifth, some groups had a very small number of patients, and especially of females, patients with primary spontaneous pneumothorax, and patients with a lesion in the lower lobes. Finally, chart review and data collection (besides radiological data) were performed by an investigator who was not blinded to the study outcomes, and this may have been a source of bias.
 
We conclude that EBV implantation via the flexible bronchoscope can be useful in hastening air-leak cessation in patients with persistent air leak complicating spontaneous pneumothorax. Only about one-fifth of subjects, however, showed unequivocal benefit, and safety of this form of treatment needs further evaluation. Bilateral intact interlobar fissures seem to be a necessary, though not sufficient, condition for treatment success, and patients with fewer medical co-morbidities and immediate air-leak cessation after completion of EBV implantation seem to have a higher likelihood of treatment success. Further evaluation by randomised controlled trials is warranted.
 
Acknowledgements
We thank the doctors and nurses of the Respiratory Team, Princess Margaret Hospital, for taking care of the patients, and nurses of the Central Endoscopy Unit, Princess Margaret Hospital, for providing technical support for the bronchoscopy procedures.
 
Declaration
The authors have no conflicts of interest to disclose.
 
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Effect of a financial incentive on the acceptance of a smoking cessation programme with service charge: a cluster-controlled trial

Hong Kong Med J 2018 Apr;24(2):128–36 | Epub 4 Apr 2018
DOI: 10.12809/hkmj176960
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Effect of a financial incentive on the acceptance of a smoking cessation programme with service charge: a cluster-controlled trial
KS Wong, MB, BS1; SN Fu, MB, BS, MFM2; KL Cheung, MB, ChB2; MC Dao, MB, BS2; WM Sy, MB, BS2
1 Family Medicine and General Out-patient Clinics, Kowloon Central Cluster, Hospital Authority, Hong Kong
2 Family Medicine & Primary Health Care, Kowloon West Cluster, Hospital Authority, Hong Kong
 
Corresponding author: Dr KS Wong (wks638@ha.org.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Frontline health care professionals in Hong Kong may encounter high refusal rates for the Hospital Authority’s Smoking Counselling and Cessation Programme (SCCP) when smokers know it is subject to a service charge. We compared SCCP booking and attendance rates among smokers with or without a financial incentive.
 
Methods: In this multicentre non-randomised cluster-controlled trial, adult smokers who attended one of six general out-patient clinics between November 2015 and April 2016 were invited to join an SCCP. Attendees in the three intervention-group centres but not the three control-group centres received a supermarket coupon to offset the service charge.
 
Results: A total of 173 smokers aged 18 years or older (92 in the intervention group and 81 in the control group) were recruited into the study. In the intervention group, 47 smokers (51%) agreed via a questionnaire that they would join the SCCP, compared with only 23 smokers in the control group (28%). The booking rates were 83% (n=39) in the intervention group and 83% (n=19) in the control group. Among those who had booked a place, 19 (49%) intervention-group participants and 11 (58%) control-group participants attended an SCCP session. Multivariable logistic regression revealed that offering a coupon was associated with agreeing to join an SCCP (odds ratio=4.963, 95% confidence interval=2.173-11.334; P<0.001) and booking an SCCP place (odds ratio=4.244, 95% confidence interval=1.838-9.799; P<0.001).
 
Conclusion: Provision of a financial incentive was positively associated with agreement to join an SCCP and booking an SCCP place. Budget holders should consider providing the SCCP free of charge to increase smokers’ access to the service.
 
 
New knowledge added by this study
  • This study reveals that provision of a financial incentive to offset the service charge of the Smoking Counselling and Cessation Programme in Hong Kong might increase the proportion of smokers who agree to join the programme and make an appointment.
Implications for clinical practice or policy
  • Budget holders should consider providing a free Smoking Counselling and Cessation Programme to increase smokers’ access to the service.
 
 
Introduction
There is no doubt that smoking is a serious hazard to health.1 2 3 One in two smokers will be killed by smoking; if one can help two smokers to quit, at least one life will be saved.4 Individual counselling by trained therapists can assist smokers to quit.5 6 7 The counselling usually involves review of the participant’s smoking history and motivation to quit, provision of problem-solving strategies to deal with high-risk situations, and encouragement. Smokers who receive individual counselling are 39% more likely to cease smoking in the long term than smokers who receive minimal behavioural intervention.5 Another method to increase the smoking cessation rate is nicotine replacement therapy (NRT). Such therapy (eg, gum, transdermal patch, and lozenges) is cost-effective in smoking cessation and increases the rate of quitting by 50% to 70%.8 9 10 11 Combining counselling and pharmacotherapy has been shown to further increase smoking cessation success rates by more than 80% when compared with minimal intervention or usual care.12 If a smoker quits smoking in the absence of external assistance, there is only a 3% to 5% chance of sustained abstinence at 6 to 12 months.13
 
In Hong Kong, the Smoking Counselling and Cessation Programme (SCCP) consists of individual counselling and provision of NRT and is available from the Hospital Authority; similar services are also provided by the Department of Health and the Tung Wah Group of Hospitals.14 The Hospital Authority operates 58 smoking cessation and counselling centres. Despite this available support, only about 19% of current smokers in Hong Kong have tried a smoking cessation service.15 In contrast, the prevalence of assisted quit attempts was 59.4% in Australia in 2008-2009 and 53.6% in the United Kingdom in 2010.16
 
The SCCP in Hong Kong is offered as part of chronic care, and general out-patient clinics (GOPCs) provide a good opportunity for health care professionals to refer smokers to an SCCP. Frontline GOPC health care professionals in Hong Kong may encounter high refusal rates of SCCP service when smokers know they must pay a service charge. Currently, smoking cessation and counselling centres SCCC charge HK$50 [~US$6.40] (HK$45 [~US$5.80] at the time of this study) for an initial face-to-face consultation, unless the client is exempt (eg, those receiving the Comprehensive Social Security Allowance or civil servants). There is no extra charge for NRT.
 
A review article in the Cochrane Library by Reda et al17 proposed that if all costs to smokers are covered, the proportion of smokers who attempt to quit, use smoking cessation treatments, and succeed in quitting will significantly increase compared with provision of no financial support. Reda et al17 also suggested that even though the absolute differences in quitting were small when an intervention group was compared with a control group (total events: 134 of 1409 vs 75 of 1351, respectively), the costs per person successfully quitting were low or moderate (US$119 to US$6450). However, all the studies included in that review were conducted in western countries, where the health care financing systems may differ from that of Hong Kong. In this study, we aimed to determine whether the booking and attendance rates at a smoking cessation service (SCCP) in a primary care setting could be increased if the patient received a financial incentive, as payment-in-kind, to offset the service fee.
 
Methods
Study design and population
This was a multicentre non-randomised cluster-controlled trial involving six GOPCs of the Hong Kong Hospital Authority’s Kowloon West Cluster and conducted from November 2015 to April 2016. The study protocol was approved by the Hospital Authority Kowloon West Cluster Research Ethics Committee (Ref No. KW/EX-15-169(91-08)). Non-random cluster sampling was used to choose participating clinics and assign them to study group, in order to avoid contamination of participants between the intervention and control groups. Three clinics (Ha Kwai Chung GOPC, West Kowloon GOPC, and Tsing Yi Cheung Hong GOPC) were assigned to the intervention group and three (Cheung Sha Wan GOPC, Li Po Chun GOPC, and South Kwai Chung GOPC) to the control group. A standard regular SCCP was available at all six clinics. The SCCP counsellors were trained nurses or pharmacists and all underwent the same smoking cessation counselling training provided by the Hospital Authority Head Office. The GOPC staff and SCCP counsellors were not involved in clinic selection or assignment.
 
The study centres were six of the 73 government-funded primary care GOPCs, and the majority of their patients were from a lower socio-economic class or older patients with chronic illnesses. The patient profiles from the six GOPCs shared a similar socio-demographic background and disease profile. There was no pre-study SCCP booking rate available, but the total number of smokers recruited from the three control clinics into the SCCP during the study period was similar to the number of SCCP referrals made by the three clinics during an equivalent period in the previous year (November 2014 to April 2015). The attendance rate for booked SCCP appointments was logged by the clinic computer system and was 50% to 60% among all six clinics.
 
Convenience sampling was used to recruit current smokers at the time of recruitment,15 who were identified during a doctor’s consultation or nurse’s assessment during the daytime. Information about this study and possible recruitment of patients for SCCP referral was given to doctors and nurses before the start of the study. After valid consent had been obtained, participants were invited to complete a questionnaire to provide background information, smoking status, and decision to join an SCCP. Assistance was given with the questionnaire if required. The questionnaires distributed to the control group (online supplementary Appendix 1) and the intervention group (online supplementary Appendix 2) stated the usual SCCP service charge of HK$45. The intervention group’s questionnaire additionally stated that a HK$50 supermarket coupon would be given to SCCP attendees. Those who agreed to participate in the SCCP were directed to make an appointment via the registration counter.
 
The SCCP counsellors in the intervention group were briefed by the authors about the process of issuing a supermarket coupon as payment in-kind to SCCP attendees. The SCCP session was carried out as usual, regardless of study group. In clinics in the intervention group, the supermarket coupon was given to SCCP participants after payment of the service charge.
 
Inclusion and exclusion criteria
Current smokers who were aged 18 years or older were eligible for the study. Participants were excluded if (1) the SCCP service charge was waived—for example, if they were a Comprehensive Social Security Allowance recipient or a civil servant; (2) they were as mentally incapacitated and unable to give consent; or (3) they were pregnant, as there was concern that NRT may increase the risk of congenital respiratory anomalies.18
 
Recruitment questionnaire
A structured questionnaire in traditional Chinese script (online supplementary Appendices 1 and 2) was used to collect the following information:
(1) Age, sex, mean personal monthly income, and whether the participant thought the clinic was a convenient place to go;
(2) Smoking history: age when starting smoking, number of years of smoking, the mean number of cigarettes consumed per day (CPD), and time to the first cigarette of the day (TTFC) after waking. The nicotine dependence level was measured by CPD and TTFC, which have been shown to be independent predictors of quitting outcome.19 A categorical scoring method has been deemed adequate for many purposes19 and was adopted in this study (CPD categories of 0-10, 11-20, 21-30, and ≥31; TTFC categories of ≤5, 6-30, 31-60, and ≥61 minutes);
(3) Rating (range, 0-10) of perceived importance of, readiness for, and confidence in smoking cessation, which have been reported to be associated with smoking behavioural change20;
(4) If the smoker agrees to join the SCCP.
The questionnaire comprised 14 questions. The relevance and content validity of the questionnaire were reviewed by senior doctors. It was also pilot-tested in 10 smokers for face validity.
 
Outcome measures
The rates of agreement between questionnaire response rate for intention to book an SCCP appointment, actual SCCP booking rate via the registration counter, and SCCP attendance rate were compared between the intervention and control groups. Defaulters or participants who rescheduled their SCCP sessions outside the study period were treated as non-attendees. Smokers who joined the SCCP were followed up by telephone by smoking-cessation counsellors on the seventh day after the first consultation to enquire whether they had quit smoking and were not smoking on the day of the call. This is a standard outcome measure of the SCCP used by the Hospital Authority.
 
Sample-size calculation
The sample size was based on the annual quit rate of smokers in 2014 (of 9.6%) for all GOPCs under the Hospital Authority, according to an internal report. In a Cochrane review of health care financing systems to increase the uptake of tobacco-dependence treatment, full financial interventions (ie, covering all costs) directed at smokers could increase abstinence rate at 6 months or longer by 2.45 times that of smokers with no financial intervention (risk ratio=2.45, 95% confidence interval [CI]=1.17-5.12, I2=59%, 4 studies).17 In a study by Kaper et al,21 the adjusted odds ratio for abstinence after reimbursement was 2 to 4 times that after no reimbursement. It was thus estimated that offering reimbursement to attend an SCCP would triple the programme attendance rate. Using the formula established by Casagrande et al,22 65 participants were required in each group in order to obtain an alpha of 0.05 and 80% power. Assuming a 20% attrition rate, 80 participants were required in each group.
 
Statistical analysis
Data analysis was performed with SPSS (Windows version 20.0; IBM Corp, Armonk [NY], United States). The level of significance was set at 5%. Data of the intervention and the control groups were summarised by descriptive statistics. Categorical variables were expressed as percentages and compared between the two groups by Pearson’s chi-square test or Fisher’s exact test. Continuous variables were tested for normality with Shapiro-Wilk’s test. Normally distributed variables were expressed as means with standard deviations and compared with Student’s t test. Variables that were non-normally distributed were presented as medians with interquartile ranges and compared with the Mann-Whitney U test. The association between participants’ characteristics, reimbursement, and outcomes were studied by univariate logistic regression analysis and multivariable logistic regression analysis using backward elimination, yielding crude odds ratios (ORs) and 95% CIs. Intention-to-treat analysis was used, and missing data were handled by listwise deletion.
 
Results
Participant recruitment
In the control group clinics, a total of 90 smokers were approached, of whom two refused to participate in the study (response rate, 98%). Seven were excluded, as their questionnaires were incomplete or their SCCP fee would have been waived. In the intervention group clinics, a total of 151 smokers were approached, of whom 28 refused to participate in the study (response rate, 81%). Thirty-one were excluded, as their questionnaires were incomplete or their SCCP fee would have been waived. There were 81 and 92 smokers (total, 173) recruited into the control group and intervention group, respectively.
 
Study population characteristics
There was no statistical difference between the two groups in terms of sex; age when starting smoking; mean cigarette consumption per day; TTFC; perceived importance of, readiness for, and confidence in smoking cessation; perceived convenience of clinic location; mean monthly income; and waiting time for SCCP (Table 1). More than 90% of participants were male, had a mean monthly income of <HK$30 000, and believed that the SCCP clinic was conveniently located. The median age at starting smoking was 18 years. Nearly half of the smokers were medium smokers, consuming 11 to 20 CPD. The TTFC was less than 31 minutes for more than 67% of smokers. The rating (from 0 to 10) of perceived importance of, readiness for, and confidence in quitting was 5, 3, and 4, respectively. The waiting time for an SCCP appointment was longer than 1 month for over 65% of participants.
 

Table 1. Baseline characteristics of participants
 
The age and the duration of smoking of the participants were statistically different between the two groups. The mean age of the control group was 4 years older than that of the intervention group (61.6 vs 57.6 years; P=0.048). The mean duration of smoking in the control group was 4 years longer than that in the intervention group (41.4 vs 36.9 years; P=0.047).
 
Outcomes
The Figure summarises the SCCP booking and attendance rates. In the intervention group, 47 smokers (51%) indicated on the questionnaire their agreement to join an SCCP, whereas only 23 smokers (28%) did so in the control group. Of those who agreed in principle, 39 (83%) in the intervention group made a booking compared with only 19 (83%) in the control group. For those who had booked an SCCP place, 19 (49%) and 11 (58%) attended the sessions in the intervention and control group, respectively. Three smokers (16%) in the intervention group were lost to follow-up and were counted as non-quitters. Four smokers (21%) in the intervention group and two (18%) in the control group quit successfully by the seventh day.
 

Figure. Outcomes of participants
 
Univariate logistic regression analysis (Table 2) revealed that the financial intervention was associated with a higher rate of agreeing to join an SCCP (OR=2.634, 95% CI=1.399-4.959; P=0.003) and booking of an SCCP appointment (OR=2.401, 95% CI=1.242-4.644; P=0.009), but not with attending an SCCP. Factors that were associated with a higher rate of agreeing to join, booking, and attending an SCCP session were consuming 11 to 20 CPD and higher ratings of perceived readiness for and confidence in smoking cessation. Other factors that were associated with a higher rate of agreeing to join and booking an SCCP session were ≤5 minutes for TTFC and higher rating of perceived importance of smoking cessation.
 

Table 2. Results of univariate logistic regression analysis of association between participants’ characteristics, financial intervention, and outcomes
 
Multivariable logistic regression analysis (Table 3) revealed that the financial intervention was associated with a higher rate of agreeing to join an SCCP (OR=4.963, 95% CI=2.173-11.334; P<0.001) and of booking an SCCP appointment (OR=4.244, 95% CI=1.838-9.799; P<0.001), but not with actual attendance. Higher ratings of smokers’ perceived readiness for smoking cessation was associated with a higher rate of agreeing to join, booking, and attending an SCCP session. Other factors that were associated with a higher rate of agreeing to join an SCCP and making a booking were ≤5 minutes and 6-30 minutes of TTFC and a mean monthly income of HK$10 000-29 999. Mean cigarette consumption of 11 to 20 CPD was associated with a higher rate of attendance at an SCCP.
 

Table 3. Results of multivariable logistic regression analysis of association between participants’ characteristics, financial intervention, and outcomes
 
Discussion
In Hong Kong, there are so far no published data on the effect of reimbursement on booking and attendance rates for smoking cessation programmes. Overseas studies have evaluated the effect of reimbursement on quitting attempts and abstinence rates, but not attendance at smoking cessation services. This study provides some insights into this area.
 
The participants in the control and intervention group were comparable except for mean age (62 vs 58 years) and duration of smoking (41 vs 37 years). Simply offsetting the HK$45 SCCP fee with a HK$50 supermarket coupon significantly increased smokers’ willingness to join or actually book an SCCP session (OR=4.963 and 4.244, respectively) [Table 3]. This finding suggests that a financial intervention may make more smokers consider joining an SCCP. With further counselling and NRT in the SCCP, the road to successful smoking cessation may be shortened.
 
The lack of an association between attendance rate and reimbursement might be explained by the waiting time for SCCP (Table 4). Owing to human resource constraints, more than 65% of SCCP appointments had to be scheduled for over a month after participant recruitment. The mean waiting time was 37 days for the intervention group and 33 days for the control group. The attendance rate dropped from 69% to 37% when the appointment date was over a month away. This finding was in keeping with an overseas study that reported long waiting times as one of the reasons for non-attendance at a quitting programme.23 Future local studies might involve exploring the reasons for programme non-attendance and would help service providers to improve the SCCP and help more smokers quit.
 

Table 4. Waiting time for Smoking Counselling and Cessation Programme appointment and attendance rate
 
In a local evaluative study of the integrated smoking cessation services of the Tung Wah Group of Hospitals in 2011, the majority of clients (52.6%) consumed 11-20 CPD.24 More than half (54.4%) of those who attended smoking cessation clinics of the Tung Wah Group of Hospitals had a high dependency on nicotine.24 In agreement, our study found that smokers consuming 11-20 CPD were significantly more likely to attend an SCCP than lighter smokers (OR=4.443). We also found that smokers with shorter TTFC were significantly more likely to agree to join or book an SCCP session (TTFC ≤5 minutes: OR=9.788 and 9.871, respectively; TTFC 6-30 minutes: OR=3.954, and OR=4.916, respectively).
 
Individuals in the quitting preparation stage display the highest motivation-ruler ratings.20 In our study, smokers with a higher rating of readiness were more likely to have a higher rate of deciding to join, book, or attend an SCCP (Table 3). This finding indicates that smokers who were recruited to join an SCCP were prepared to quit. Concerns that offering a financial incentive might invite smokers who had no genuine intention to quit are unfounded. Offering help to smokers for quitting was one of the MPOWER (Monitor, Protect, Offer, Warn, Enforce, and Raise) measures described by the World Health Organization to combat the global tobacco epidemic.25 Hong Kong is fortunate to have a well-established smoking cessation programme, so the service deserves to be fully used.
 
Limitations
The smokers recruited into this study were a convenience sample of attendees at GOPCs, so their characteristics would differ from those of the general smoking population in Hong Kong15 in terms of a larger proportion of males (90.8% vs 83.9%), higher daily cigarette consumption (48.6% consuming 11-20 CPD vs 56.0% consuming 1-10 CPD), and larger proportion of economically inactive smokers (38.7% vs 21.0%). The results thus may not be generalised to the whole population of Hong Kong smokers. Furthermore, retirement and economic inactivity may influence smoking habits26 and act as confounders, but these were not controlled in the multivariable analyses.
 
The control and intervention groups were not very comparable: the control group was slightly older and had smoked for slightly longer. Estimation of the sample size was suboptimal, as the total numbers of eligible smokers during the recruitment period and the estimated increase in attendance rate by financial incentives were not available before the study. Sample-size estimation was based on abstinence rates from previous studies instead of attendance rates. The number of participants who actually attended (19+11=30) may be too small to show any statistical difference between SCCP attendance rates because the difference was less than the three-fold increase for the sample-size calculation.
 
In addition, the SCCP service in some clinics was restricted to certain days or times of the week owing to availability of counsellors. Some smokers, especially those who were working, may not have been able to find a session at a convenient time. This situation could have affected the booking and attendance rate between different clinics. In one of the returned questionnaires in which the participant ticked the box “agree to join SCCP” but did not make a booking, there was a written remark in Chinese: “Time does not fit”.
 
This study was non-randomised and the doctors and nurses were not blinded to the financial intervention, because of the difficulty of running a complex workflow with limited resources. We assumed all doctors and nurses tried their best to assist smokers to quit. The possibility that those in the intervention group were more passionate in persuading patients to quit smoking cannot be excluded. The assignment of participants to the intervention or control group was not random and may explain the differences in the baseline characteristics of participants in the two groups. Moreover, it is unknown whether there would be a difference in behaviour if free SCCP was offered from the beginning, instead of providing a fixed-amount HK$50 supermarket coupon that offered an extra HK$5. Only the 7-day quit rate was used as the final programme outcome, as it was a standard outcome in the study centres. Future research with a robust randomisation process may be considered, as well as the use of longer abstinence periods such as 1 month, 3 months, and 12 months.
 
Conclusion
This study revealed that provision of a financial incentive that would indirectly cover the SCCP service fee might increase the proportion of smokers who agree to attend and make a booking to attend an SCCP. To reduce the barriers to accessing an SCCP service, budget holders should consider providing free and timely SCCP to motivated smokers. It is essential to catch smokers’ moment of hesitation and to increase their access to the service.
 
Supplementary information
Online supplementary information (Appendices 1 and 2) is available for this article at www.hkmj.org.
 
Acknowledgements
We thank the Hong Kong College of Family Physicians (HKCFP) for granting the HKCFP Trainee Research Fund 2015 for this study. We also thank the doctors and nurses in Cheung Sha Wan GOPC, Ha Kwai Chung GOPC, Li Po Chun GOPC, West Kowloon GOPC, South Kwai Chung GOPC, and Tsing Yi Cheung Hong GOPC for participant recruitment; Drs LS Chu, T Fong, KM Ho, and SY Tse for advice during research design; and Ms Ellen Yu and Mr Edward Choi for their support during the statistical analyses.
 
Declaration
The authors have no conflicts of interest to disclose.
 
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Reduction of operative mortality after implementation of Surgical Outcomes Monitoring and Improvement Programme by Hong Kong Hospital Authority

Hong Kong Med J 2018 Apr;24(2):137–44 | Epub 6 Apr 2018
DOI: 10.12809/hkmj177118
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Reduction of operative mortality after implementation of Surgical Outcomes Monitoring and Improvement Programme by Hong Kong Hospital Authority
WC Yuen, FHKAM (Surgery)1; K Wong, MSc2; YS Cheung, FHKAM (Surgery)3; Paul BS Lai, FHKAM (Surgery)3
1 Department of Surgery, Ruttonjee and Tang Shiu Kin Hospital, Hospital Authority, Hong Kong
2 Jockey Club School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
3 Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
 
Corresponding author: Prof Paul BS Lai (paullai@surgery.cuhk.edu.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Since 2008, the Hong Kong Hospital Authority has implemented a Surgical Outcomes Monitoring and Improvement Programme (SOMIP) at 17 public hospitals with surgical departments. This study aimed to assess the change in operative mortality rate after implementation of SOMIP.
 
Methods: The SOMIP included all Hospital Authority patients undergoing major/ultra-major procedures in general surgery, urology, plastic surgery, and paediatric surgery. Patients undergoing liver or renal transplantation or who had multiple trauma or massive bowel ischaemia were excluded. In SOMIP, data retrieval from the Hospital Authority patient database was performed by six full-time nurse reviewers following a set of precise data definitions. A total of 230 variables were collected for each patient, on demographics, preoperative and operative variables, laboratory test results, and postoperative complications up to 30 days after surgery. In this study, we used SOMIP cumulative 5-year data to generate risk-adjusted 30-day mortality models by hierarchical logistic regression for both emergency and elective operations. The models expressed overall performance as an annual observed-to-expected mortality ratio.
 
Results: From 2009/2010 to 2015/2016, the overall crude mortality rate decreased from 10.8% to 5.6% for emergency procedures and from 0.9% to 0.4% for elective procedures. From 2011/2012 to 2015/2016, the risk-adjusted observed-to-expected mortality ratios showed a significant downward trend for both emergency and elective operations: from 1.126 to 0.796 and from 1.150 to 0.859, respectively (Mann-Kendall statistic = –0.8; P<0.05 for both).
 
Conclusion: The Hospital Authority’s overall crude mortality rates and risk-adjusted observed-to-expected mortality ratios for emergency and elective operations significantly declined after SOMIP was implemented.
 
 
New knowledge added by this study
  • A Surgical Outcomes Monitoring and Improvement Programme allows monitoring of performance and fair comparison of individual Hospital Authority hospitals against the overall Hospital Authority average. It enhances the understanding of surgical performance and helps identify areas for improvement.
  • The Hospital Authority’s overall crude mortality rates and risk-adjusted observed-to-expected mortality ratios for emergency and elective operations significantly declined after SOMIP was implemented.
Implications for clinical practice or policy
  • A properly organised, risk-adjusted clinical audit can accurately measure surgical outcomes and provide information for surgeons to deliver quality improvement.
 
 
Introduction
Audits of surgical mortality are used worldwide to monitor surgical outcome and achieve quality assurance.1 By measuring and comparing properly collected, risk-adjusted surgical outcome data, quality of surgical care could be enhanced in participating institutions.2 It has been demonstrated in several countries that adoption of a national surgical audit programme can reduce mortality.2 3
 
The Hong Kong Hospital Authority (HA) was established in 1991. It is a government statutory body responsible for the management of 42 public hospitals and institutions, 47 specialist out-patient clinics, and 73 general out-patient clinics in Hong Kong. Seventeen HA hospitals have surgical departments; all of them provide an elective surgery service and 14 also provide an emergency surgical service. In 2016, over 80% of all hospital admissions in Hong Kong were under the management of the HA.4 Therefore, it is important for the HA to develop tools with which to measure and improve performance. For this purpose, the HA Coordinating Committee of Surgery set up a Central Surgical Audit Unit in 2001. From 2002 to 2007, the unit conducted clinical audits based on retrospective cumulative data to compare the performance of the 17 surgical departments. One to two major or ultra-major operations, such as major hepatectomy, oesophagectomy, and major lung resection, were selected each year for comparison. The risk-adjustment model used was based on the Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity (POSSUM).5 6 Those audits were procedure-based and mainly focused on mortality, and hence a more comprehensive risk-adjusted outcome audit was needed.
 
In 2008, a new programme—namely, the Surgical Outcomes Monitoring and Improvement Programme (SOMIP)—was launched by the HA with the aim of monitoring and improving surgical quality. The programme was governed by a steering committee comprising surgeons, an anaesthetist, a physician, administrative managers, and statisticians. Risk-adjusted mortality and morbidity rates of elective and emergency major and ultra-major operations at each hospital are measured and reported yearly. An annual forum is held to disseminate the results and allow the sharing of best practices.
 
This study aimed to assess the changes in overall surgical outcomes for patients after implementation of SOMIP.
 
Methods
Between July 2008 and June 2016, SOMIP captured data of all elective and emergency major/ultra-major operations (except those in children younger than 1 year) that were performed by general surgery, urology, plastic and reconstructive surgery, and paediatric surgery teams at all 17 HA hospitals. A total of 230 variables were collected from each patient: 10 patient demographic variables, 83 preoperative and operative variables, 31 laboratory test results, and 40 postoperative events and 66 postoperative adverse events in the first 30 days after surgery. Demographic data and laboratory test results were mostly automatically retrieved from various HA clinical information systems. For data that required manual retrieval, six full-time SOMIP nurse reviewers were employed by the HA head office for this purpose. Preoperative and operative variables, as well as postoperative complications occurring up to 30 days after the index operation, were retrieved from patient records by the SOMIP nurse reviewers. Mortality at 30 days, 60 days, and 90 days were also retrieved from the HA electronic database. These data were endorsed and submitted by each surgical department’s surgical supervisor within 60 days of surgery.
 
Both the manually captured and automatically captured data were entered into a tailor-made SOMIP electronic database. Data variable definitions were listed in the operation manual of the programme. To ensure data validity and consistency, all nurse reviewers completed comprehensive training on data definition and criteria, and regular nurse reviewer meetings were held to clarify any queries. All data were endorsed by the surgical supervisor of the respective surgical department. When necessary, data definitions were modified.
 
An inter-rater reliability test was performed each May and completed within a month so as to ensure consistency among nurse reviewers as well as data accuracy. Fifty cases were sampled for evaluation using a stratified systematic sampling method. For those selected cases, an independent nurse from the SOMIP team repeated the data collection using a designated data template, without prior knowledge of the information recorded by the original nurse reviewer. Data quality was measured by comparing two sets of data, and inferred by a score defined as the percentage of agreement between nurse reviewer and the SOMIP working team for each data item. The mean score of all data items was used to assess overall performance. The overall result was satisfactory and the mean score of all data items was 99.3% (range of individual item scores, 95.2%-100%).
 
Among the variables collected, preoperative risk factors including demographic data; general health and lifestyle variables; and major respiratory, cardiovascular, hepatobiliary, renal, vascular, central nervous system, and immune co-morbidities were deemed particularly important. These risk factors were modified from those in the American College of Surgeons National Surgical Quality and Improvement Program (NSQIP) to suit the local context.7 8 9 Operative variables included intra-operative blood loss, American Society of Anesthesiologists physical status classification, procedure complexity score, surgical subspecialty, wound classification, operative magnitude, and operative time. Before analysis and reporting, SOMIP data were cleaned and verified by four surgeons and the SOMIP surgical supervisors of each hospital. Questionable cases were reviewed accordingly. Cases of liver transplantation, renal transplantation, multiple trauma, and major bowel ischaemia (Table 1)10 11 12 13 14 15 16 17 were excluded from the risk-adjusted model analysis.
 

Table 1. No. of cases excluded and reasons, from 2008/2009 to 2015/201610 11 12 13 14 15 16 17
 
Comparative risk-adjusted models (different models for emergency operations and elective operations) were generated using hierarchical logistic regression. The 30-day risk-adjusted mortality models expressed hospital performance as expected odds ratios. A risk-adjusted observed-to-expected mortality ratio (O/E ratio) was then calculated for each hospital. The O/E ratio is a quotient between the observed number of deaths and the expected number of deaths; the latter was calculated by a logistic regression method based on significant independent risk factors. Together with the 90% confidence intervals, O/E ratios were depicted by caterpillar plots and boxplots. Hospitals with the lower limit of the 90% confidence interval of O/E ratios greater than 1 were defined as ‘high outliers’; hospitals with the upper limit of the 90% confidence interval of O/E ratios lower than 1 were defined as ‘low outliers’. The risk-adjusted outcome of a ‘high-outlier’ hospital was probably worse than the average outcome, and that of a ‘low-outlier’ hospital was probably better than the average outcome.
 
In addition to risk-adjusted postoperative mortality, various general medical and surgical complications, as well as specific complications (anastomotic leakage, surgical site infection, acute myocardial infarction, pneumonia), were recorded. The list of complications recorded and the method to derive the SOMIP risk-adjustment model have been described in detail in the annual SOMIP Report.10 11 12 13 14 15 16 17 Different levels of confidence were used for different outcome variables—90% confidence interval for mortality rates, 95% confidence interval for major complications, and 99% confidence interval for morbidity rates. Using SOMIP data together with other useful information extracted from the HA Executive Information System (eg, bed occupancy, nursing manpower, intensive care unit support, and surgeon workload), root-cause analyses were performed using multilevel logistic regression, as described in the annual SOMIP Report.10 11 12 13 14 15 16 17
 
The discriminative power of the risk-adjusted models was measured by the C-index, area under the receiver-operating characteristic curve (AUC). The closer the C-index is to 1, the better the discriminative power of the model is: a C-index of ≥0.8 indicates excellent discriminative power.18 The calibration accuracy of the models was assessed by the Hosmer-Lemeshow goodness-of-fit test (HL test). The calibration of the model was rejected if P<0.05. The Mann-Kendall non-parametric trend test was used to identify trends (positive or negative) in the annual data series for both crude mortality rates (2009/2010 to 2015/2016) and risk-adjusted O/E ratios (2011/2012 to 2015/2016). A very high positive value of the Mann-Kendall statistic (S) indicated an increasing trend; a very low negative value indicated a decreasing trend. The test statistic Z-score was used as a measure of trend significance.
 
Results
Descriptive data
Age distribution trends are summarised in Table 2.10 11 12 13 14 15 16 17 From 2008/2009 to 2015/2016, the proportion of people aged 61-70 years increased by 7 percentage points (from 19% to 26%), whereas the proportions of people aged 41-50 years and 71-80 years decreased by 2 and 5 percentage points, respectively.
 

Table 2. Distribution of patients by age-group, from 2008/2009 to 2015/2016.10 11 12 13 14 15 16 17
 
Table 310 11 12 13 14 15 16 17 shows proportions of patients taking regular medication for diabetes mellitus and hypertension before surgery from 2009/2010 to 2015/2016, as well as those currently smoking (within 1 year) and drinking more than 2 units of alcohol per day in the previous 2 weeks. Over 70% of patients had at least one of these four conditions, whereas about 40% had a history of regular use of hypertension medication before surgery.
 

Table 3. Distribution of patients by habit before surgery/admission, from 2009/2010 to 2015/201610 11 12 13 14 15 16 17
 
Annual numbers of elective operations by specialty are summarised in Table 4.10 11 12 13 14 15 16 17 For the 10 listed elective operations, the most frequently performed were in urology, consistently constituting 28% of the caseload from 2008/09 to 2015/16. The least frequently performed procedures were parotid surgery (1%) and paediatric surgery (1%).
 

Table 4. Elective operations by specialty, from 2008/2009 to 2015/201610 11 12 13 14 15 16 17
 
Overall crude mortality rates and risk-adjusted observed-to-expected mortality ratios
From July 2008 to June 2016, eight SOMIP reports were published.10 11 12 13 14 15 16 17 They showed that the HA overall crude mortality rate approximately halved over this time. The crude 30-day mortality rate for emergency operations dropped gradually from 10.8% in the year 2009/2010 to 5.6% in 2015/2016 (Fig 1). Similarly, the crude 30-day mortality rate for elective operations more than halved: from 0.9% in 2009/2010 to 0.4% in 2015/2016 (Fig 2).
 

Figure 1. Crude 30-day mortality rates for emergency operations, 2009/2010 to 2015/2016
 

Figure 2. Crude 30-day mortality rates in elective operations, 2009/2010 to 2015/2016
 
In the 5-year cumulative comparison analysis (2011/2012 to 2015/2016), both models had excellent discriminative power and good calibration accuracy. For emergency operations, the AUC was >0.9 and the HL test statistic was >0.1; for elective operations, the AUC was >0.89 and the HL test statistic was >0.2. The risk-adjusted observed-to-expected 30-day mortality ratio for both types of surgery showed a similar downward trend to the crude mortality rates. For emergency operations, the risk-adjusted O/E ratios were 1.126, 1.022, 1.113, 0.921, and 0.796 across the 5 years (Fig 3). These values show a statistically significant downward (negative) trend (S= –0.8; P<0.05). The results of the Mann-Kendall analyses are summarised in Table 4. For elective operations, risk-adjusted O/E ratios were 1.150, 1.229, 0.881, 0.862, and 0.859 across the 5 years (Fig 4). These values show a statistically significant downward (negative) trend (S= –0.8; P<0.05) [Table 5].
 

Figure 3. Risk-adjusted observed-to-expected 30-day mortality ratio for emergency operations, 2011/2012 to 2015/2016
 

Figure 4. Observed-to-expected 30-day mortality ratio for elective operations, 2011/2012 to 2015/2016
 

Table 5. Mann-Kendall non-parametric trend test results
 
Discussion
Before the turn of the century, most hospital records in HA hospitals were handwritten and retained by individual hospitals. There was no convenient means by which to share patient details among hospitals. Around 2001, the HA implemented a number of clinical management electronic systems, such as the electronic patient record, Operation Theatre Record System, and Clinical Data Analysis and Reporting System, at all HA hospitals. By virtue of this infrastructure, patient records and information about diagnoses and operations could be accessed at a central level. Based on this central clinical database, a Quality Assurance Subcommittee under the Coordinating Committee of Surgery commenced small-scale comparative clinical audits for ultra-major operations in 2002, focusing on one to two ultra-major operations per year. The audits provided basic information about hospital performance for the selected operation, such as number of procedures, age distribution of patients, and mortality rate.
 
Subsequently, the Coordinating Committee of Surgery developed a more robust system to monitor more major operations at the same time. It was decided to follow the framework of NSQIP, which was developed in 1994 by the Veterans Affairs Hospitals in the United States to monitor risk-adjusted surgical operation outcomes. Like HA hospitals, Veterans Affairs Hospitals are managed by a central governing body and equipped with a comprehensive electronic medical records system. Studies19 20 showed a significant improvement in both mortality and morbidity over time and thus, in 2004, NSQIP was extended to private hospitals and endorsed by the American College of Surgeons. Using NSQIP as the blueprint, the HA launched SOMIP in 2008. The SOMIP adopted similar risk-adjustment variables, use of nurse reviewers to collect data, a focus on hospital performance rather than individual surgeon performance, and similar methods of data analysis and determination of outliers. Moreover, SOMIP allowed individual HA hospitals to benchmark their performance against the overall HA average.
 
As all surgical patients have a different health status, their operation outcomes will likewise differ. Appropriate adjustment for different patient risks is essential when interpreting hospital mortality rates. To adjust for different risk factors, over 100 patient risk factors were captured for each enrolled patient. For NSQIP, one risk-adjustment mortality model was constructed for all operations. In contrast to NSQIP, separate models were devised for emergency and elective operations in SOMIP.
 
Hospital outliers can be identified by O/E ratios if the confidence interval of the O/E ratio is greater than 1, meaning that after balancing the different risks of hospital patients, their clinical outcomes are most likely different from the rest. From the results of this study, it was encouraging to find a significant trend of reduction in crude mortality rates and O/E ratios for both elective and emergency operations at HA hospitals over the past 5 years. According to the significant reduction in expected odds ratios over the years, this improvement is genuine and not due to patient selection.
 
There are several possible reasons behind the changes: public identification as a poor performer is a strong incentive for change in HA hospitals; sharing best practices on perioperative patient care is an important educational activity that takes place annually through the SOMIP Forum; the HA Head Office invests more resources into deficient hospitals; and changing attitudes towards managing surgical complications by other colleagues from the intensive care unit are also helpful. All of these may have contributed to the change.
 
Limitations
The SOMIP has a number of limitations. The coverage of SOMIP is not as complete as that of NSQIP, since many surgical departments such as orthopaedics and neurosurgery are not included. Monitoring is done by retrospective annual case collection (from 1 July to 30 June) because it takes 13 months to complete case enrolment and an additional 3 months for data verification, model building, and statistical analysis. Because of the small number of events, the current programme is not able to determine the risk-adjusted outcomes of individual operations or surgeons. Furthermore, because this programme relies heavily on the HA central electronic database, it is not easy to extend it to hospitals without this information infrastructure. Although the trend of reduction in mortality was statistically significant, we were not able to demonstrate a causal relationship with SOMIP implementation.
 
Potential issues with data quality may have affected the outcomes. In the inter-rater reliability test, the nurse reviewers were not blinded and this may have caused information bias. Also, quality of data collection in the initial 2 years may have been unreliable. As a result, the 5-year cumulative comparison analysis for emergency and elective operations commenced from 2011/2012, rather than 2008/2009. Furthermore, data definitions are updated regularly in the operation manual and could have affected the time trend analysis. Nonetheless, the SOMIP team considered changes in data definitions to be minor and did not expect a significant impact on the risk models.
 
Mortality could be influenced by many factors; ensuring risk adjustments are adequate and appropriate would be a challenge. Disease factors, stage of disease, and treatment options may not be fully taken into account by the risk-adjusted models, and data readiness and availability are further constraints. Surgeon skill and experience was another aspect that could not be accommodated and was difficult to adjust for. In the HA, surgical operations are performed by a team; therefore, it would be difficult to separate individual surgeon experience and credentials from those of the whole team.
 
Conclusion
From 2008 to 2016, the HA’s overall crude mortality rates and risk-adjusted O/E ratios showed a significant trend of reduction for both emergency and elective operations. The SOMIP enhances understanding of surgical performance and helps identify areas for improvement. It allows individual HA hospitals to benchmark their performance against the overall HA average through risk-adjusted O/E ratios.
 
Acknowledgements
We thank the SOMIP Steering Committee of the Hospital Authority, the Coordinating Committee of Surgery, and the Biostatistics team of The Chinese University of Hong Kong for their contributions and helpful comments on this manuscript.
 
Declaration
The authors have no conflicts of interest to disclose.
 
References
1. Lui CW, Boyle FM, Wysocki AP, et al. How participation in surgical mortality audit impacts surgical practice. BMC Surg 2017;17:42. Crossref
2. Khuri SF, Daley J, Henderson W, et al. Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs surgical risk study. J Am Coll Surg 1997;185:315-27. Crossref
3. Kiermeier A, Babidge WJ, McCulloch GA, Maddern GJ, Watters DA, Aitken RJ. National surgical mortality audit may be associated with reduced mortality after emergency admission. ANZ J Surg 2017;87:830-6. Crossref
4. Hospital Authority Statistical Report (2015-16). Available from: http://www.ha.org.hk/haho/ho/stat/HASR15_16.pdf. Accessed 10 Nov 2017.
5. Copeland G, Jones D, Walters M. POSSUM: A scoring system for surgical audit. Br J Surg 1991;78:355-60. Crossref
6. Copeland G. The POSSUM system of surgical audit. Arch Surg 2002;137:15-9. Crossref
7. Khuri S, Daley J, Henderson W, et al. The National VA Surgical Risk Study: risk adjustment for the comparative assessment of the quality of surgical care. J Am Coll Surg 1995;180:519-31.
8. Daley J, Khuri SF, Henderson W, et al. Risk adjustment of the postoperative morbidity rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs surgical risk study. J Am Coll Surg 1997;185:328-40. Crossref
9. Daley J. Validating risk-adjusted surgical outcomes: site visit assessment of process and structure. J Am Coll Surg 1997;185:341-51. Crossref
10. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume One: July 2008-June 2009. Hospital Authority, Hong Kong SAR Government; 2010.
11. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Two: July 2009-June 2010. Hospital Authority, Hong Kong SAR Government; 2011.
12. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Three: July 2010-June 2011. Hospital Authority, Hong Kong SAR Government; 2012.
13. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Four: July 2011-June 2012. Hospital Authority, Hong Kong SAR Government; 2013.
14. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Five: July 2012-June 2013. Hospital Authority, Hong Kong SAR Government; 2014.
15. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Six: July 2013-June 2014. Hospital Authority, Hong Kong SAR Government; 2015.
16. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Seven: July 2014-June 2015. Hospital Authority, Hong Kong SAR Government; 2016.
17. Surgical Outcomes Monitoring & Improvement Program (SOMIP) report. Volume Eight: July 2015-June 2016. Hospital Authority, Hong Kong SAR Government; 2017.
18. Ash A, Schwartz M. Evaluating the performance of risk-adjustment methods: dichotomous variables. In: Iezzoni L, editor. Risk adjustment for measuring health care outcomes. Ann Arbor, MI: Health Administration Press; 1994: 313-46.
19. Hall BL, Hamilton BH, Richards K, Bilimoria KY, Cohen ME, Ko CY. Does surgical quality improve in the American College of Surgeons National Surgical Quality Improvement Program: An evaluation of all participating hospitals. Ann Surg 2009;250:363-76. Crossref
20. Cohen ME, Liu Y, Ko CY, Hall BL. Improved surgical outcomes for ACS NSQIP hospitals over time: evaluation of hospital cohorts with up to 8 years of participation. Ann Surg 2016;263:267-73. Crossref

Outcomes and morbidities of patients who survive haemoglobin Bart’s hydrops fetalis syndrome: 20-year retrospective review

Hong Kong Med J 2018 Apr;24(2):107–18 | Epub 6 Apr 2018
DOI: 10.12809/hkmj176336
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
ORIGINAL ARTICLE
Outcomes and morbidities of patients who survive haemoglobin Bart’s hydrops fetalis syndrome: 20-year retrospective review
Wilson YK Chan, FHKAM (Paediatrics)1; Alex WK Leung, FHKAM (Paediatrics)2; CW Luk, FHKAM (Paediatrics)3; Rever CH Li, FHKAM (Paediatrics)4; Alvin SC Ling, FHKAM (Paediatrics)5; SY Ha, FHKAM (Paediatrics), FHKAM (Pathology)1
1 Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
2 Department of Paediatrics and Adolescent Medicine, Prince of Wales Hospital, Shatin, Hong Kong
3 Department of Paediatrics and Adolescent Medicine, Queen Elizabeth Hospital, Kowloon, Hong Kong
4 Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
5 Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
 
Corresponding author: Dr Wilson YK Chan (wilsonykchan@graduate.hku.hk)
 
 Full paper in PDF
 
Abstract
Introduction: Haemoglobin Bart’s hydrops fetalis syndrome was once considered a fatal condition. However, advances over the past two decades have enabled survival of affected patients. Data relating to their morbidities and outcomes will help medical specialists formulate a management plan and parental counselling.
 
Methods: All babies with the syndrome who survived beyond the neonatal period and were subsequently managed long-term in eight public hospitals in Hong Kong from 1 January 1996 to 31 December 2015 were included. Patient and parent characteristics, antenatal care, reasons for continuation of pregnancy, intrauterine interventions, perinatal course, presence of congenital malformations, stem-cell transplantation details, and long-term neurodevelopmental outcomes were reviewed.
 
Results: A total of nine patients were identified, of whom five were female and four male. The median follow-up duration was 7 years. All were Chinese and were homozygous for the Southeast Asian α-thalassaemia deletion. Five of the nine mothers received antenatal care at a public hospital and opted to continue the pregnancy after antenatal diagnosis and counselling. Despite intrauterine transfusions, all babies were born with respiratory depression and required intubation and mechanical ventilation during the neonatal period. Hypospadias was identified in all four male infants. Growth retardation, global developmental delay, and residual neurological deficits were noted in two-thirds of the patients. Haematopoietic stem-cell transplantation was performed in two patients, who became transfusion-independent.
 
Conclusions: Survival of patients with Bart’s hydrops fetalis syndrome is possible but not without short- and long-term complications; local epidemiology is comparable to that documented for an international registry. Detailed antenatal counselling of parents with a non-judgemental attitude and cautious optimism are imperative.
 
 
New knowledge added by this study
  • This is the first territory-wide multicentre retrospective review of demographic data, morbidities, and outcome of survivors of haemoglobin Bart’s hydrops fetalis syndrome in Hong Kong.
  • Intrauterine transfusion is commonly practised in local obstetric units in an attempt to reduce fetal hypoxia and fetal-maternal complications, presumably contributing to survival.
  • Prematurity and perinatal respiratory depression are often encountered; intubation, mechanical ventilation, and exchange transfusions are beneficial. Regular hypertransfusion and optimal iron chelation are advocated. Haematopoietic stem-cell transplantation is curative but morbidities and mortalities should not be overlooked.
Implications for clinical practice or policy
  • Better patient and doctor education is needed, stressing the importance of early accurate diagnosis and the serious sequelae of late presentation.
  • Diagnosis should be considered if ultrasonographic features are clinically suggestive, regardless of parents’ mean corpuscular volume, owing to uniparental disomy or non-paternity. Clinical vigilance and prompt specialist referral for ultrasonography and accurate diagnostic testing are crucial to improve maternal-fetal outcomes.
  • For parents who opt to continue the pregnancy after diagnosis, meticulous counselling about perinatal and long-term outcomes and morbidities of survivors is imperative.
  • Multidisciplinary anticipatory care among obstetricians, pathologists, neonatologists, and haematologists promotes survival, lowers morbidity, and improves long-term outcomes. Patients can now survive beyond childhood, so adult-care physicians can expect to encounter an increasing number of referrals of adult survivors of haemoglobin Bart’s hydrops fetalis syndrome.
 
 
Introduction
Haemoglobin Bart’s hydrops fetalis syndrome (BHFS), also known as homozygous α0-thalassaemia major or homozygous α-thalassaemia 1, was first described in 1960.1 2 It was considered fatal in the 1960s to 1970s,3 and fetuses often died in utero, were stillborn or died during the early neonatal period.4 When prenatal screening and diagnosis for thalassaemia first started in Hong Kong in 1983, BHFS was advocated as an indication for termination of pregnancy.5 Nonetheless, the availability of intrauterine transfusions (IUTs)6 7 and intrauterine exchange transfusions (IUETs) enabled affected fetuses to survive the perinatal period.
 
Since the world’s first reported case of survival in 1985 in Canada,8 increasing numbers of BHFS survivors have been reported worldwide, including in Hong Kong.9 The traditional view of its fatality has been challenged,10 11 and in the 1990s there was lively debate about the ethical concerns surrounding active resuscitation and treatment of BHFS babies. Regular transfusions and iron chelation allow BHFS patients to survive even beyond adulthood, and haematopoietic stem cell transplantation12 13 14 offers a cure for this disease, albeit at the expense of possible significant morbidities and compromised quality of life. Long-term morbidities for this cohort of patients thus become an important issue to address. Information gathered by this territory-wide retrospective study will assist physicians in contemplating perinatal management and counselling of parents.
 
Methods
Data collection
The setting for this study was all eight public hospital paediatric haematology units in Hong Kong that care for patients with transfusion-dependent thalassaemia. Records of patients diagnosed with BHFS (either antenatally or postnatally) who survived beyond the neonatal period and who were subsequently managed long-term at those units from 1 January 1996 to 31 December 2015 were retrieved from the Hong Kong Hospital Authority’s Clinical Data Analysis and Reporting System using the International Classification of Diseases diagnostic code 282.7, searching only for Haemoglobin-Bart’s disease. Data cross-checking was performed with the help of the Hong Kong Paediatric Haematology and Oncology Study Group and paediatric haematologists from the eight hospitals.
 
Information about patient and parent characteristics, availability of antenatal care and diagnosis, antenatal ultrasonographic findings, reasons for continuation of pregnancy, use of intrauterine transfusions, perinatal course, presence of congenital malformations, subsequent neonatal and long-term neurodevelopmental outcome, and availability of stem-cell transplantation and subsequent outcomes were collected and studied. Patients with BHFS who were not born in Hong Kong were excluded from this study. No missing cases were identified during the 20-year study period, as confirmed from personal communications with both paediatric and adult haematologists from all public hospitals in Hong Kong. As BHFS pregnancies are considered high risk owing to possible maternal-fetal complications, it was presumed that no cases would have been managed by private doctors without support from a neonatal intensive care unit.
 
Statistical analyses
This study was primarily descriptive in nature. Statistical analyses were performed with the Statistical Package for the Social Sciences (SPSS) version 22.0 (IBM Corp., Armonk [NY], United States). Continuous variables are expressed as median and range.
 
Ethics approval
This study complied with the Declaration of Helsinki and approval was obtained from the Institutional Review Board of The University of Hong Kong / Hong Kong Hospital Authority West Cluster and all other clusters of participating hospitals. Verbal (parental) consent was obtained but formal written consent was not required by the institutional review board, as this retrospective study did not involve direct patient care (Ref No. HKUCTR-2148).
 
Results
Demographic and genetic features
Surviving patients with BHFS were identified in five of the eight local paediatric haematology units. A total of nine infants were found, of whom five were female and four male. All patients were Chinese, and all were confirmed to be homozygous for the Southeast Asian α-thalassaemia deletion. Six pairs of parents were heterozygous for the Southeast Asian deletion, and three pairs refused genetic testing, one of which was suspected to be a case of non-paternity (case 7). For case 6, the mother was heterozygous for the Southeast Asian deletion (α-thalassaemia 1), whereas the father had an α3.7 single deletion (α-thalassaemia 2). The child demonstrated maternal uniparental disomy and isodisomy (Tables 1 and 2).6 13 14 15 16 17 18 19 20
 

Table 1. Characteristics of parents of patients with haemoglobin Bart’s hydrops fetalis and reasons for continuation of pregnancy
 

Table 2. Family history, antenatal features, and genetic characteristics of survival cases of haemoglobin Bart’s hydrops fetalis
 
Prenatal diagnosis, intrauterine management, and maternal complications
Among the nine mothers, one received no antenatal care, two received antenatal care in a local private centre, and one received antenatal care in mainland China. All were considered normal and received no IUT. For the remaining five mothers who received antenatal care in a public hospital, all had BHFS diagnosed antenatally in their neonates (two by cordocentesis, one by chorionic villus sampling, one by amniocentesis, and one by both cordocentesis and chorionic villus sampling). All five couples decided to continue the pregnancy after counselling: two for religious reasons and three out of personal preference. All five patients had IUT/IUET performed two to four times. Antenatal ultrasonography of seven fetuses revealed cardiomegaly in four and hydropic changes in two, one of which subsequently resolved after IUT. Placentomegaly was detected in three mothers and polyhydramnios in one. Pre-eclampsia was reported in two mothers and was controlled with antihypertensive drugs (Tables 2 and 3).6 13 14 15 16 17 18 19 20
 

Table 3. Perinatal outcomes and morbidities in survival cases of haemoglobin Bart’s hydrops fetalis
 
Neonatal outcomes and co-morbidities
Preterm delivery occurred in seven of the nine cases, with a median gestational age at delivery of 33 weeks. All infants had respiratory depression at birth and required resuscitation, neonatal intensive care unit admission, and intubation. Surfactant for respiratory distress syndrome was required by five infants, and five demonstrated persistent pulmonary hypertension of the newborn, which required high-frequency oscillation ventilation and inhaled nitric oxide administration. Inotropic support with or without hydrocortisone was required by four infants with haemodynamic instability (poor cardiac contractility, heart failure, and/or hypotension). In case 6, the infant required cardiopulmonary resuscitation for more than 20 minutes after cardiac arrest. Postnatally, exchange transfusion was performed in five babies: two received a double-volume transfusion and three received a single-volume transfusion. Three infants received a transfusion within the first 24 hours of life. The median pre- and post-transfusion haemoglobin level was 90 and 170 g/L, respectively. All infants showed improved haemodynamic stability after transfusion. Congenital malformations were noted in all cases in this cohort (Tables 3 and 4).6 13 14 15 16 17 18 19
 

Table 4. Long-term outcomes and morbidities in survival cases of haemoglobin Bart’s hydrops fetalis
 
All four male babies had hypospadias that required urethroplasty, and two had concomitant undescended testes that required orchidopexy. Dental (case 1) and skeletal (case 3) anomalies were noted in two patients. Regarding the cardiovascular system, patent ductus arteriosus was noted in five cases and a secundum atrial septal defect in three. Regarding the digestive system, one infant (case 3) had type 3 jejunal atresia, for which end-to-end anastomosis was performed on day 4 of life. Two patients had neonatal hepatitis: one case resolved with time and the other still requires regular follow-up for elevated transaminase levels. No cases of cerebrovascular malformations were identified in this local cohort.
 
Growth, puberty, and neurodevelopment
Both survivors who have reached adulthood are of short stature and have failed to achieve their final adult height, that is, to reach their predicted mid-parental height. Nonetheless, both had a normal puberty. Among the nine survivors, two have long-term neurological deficits, both manifested as mild spastic diplegia, although not affecting mobility. Five infants had delayed development, one of whom continues to have borderline low intellect (IQ, 80-89) after reaching adulthood (case 1). Two have normal intellect (cases 2 and 4) despite the need for multidisciplinary training during infancy, and the remaining two (cases 6 and 7) are attending mainsteam schools that provide extra training and support. The two cases diagnosed most recently (cases 8 and 9) have had normal development to date (Tables 3 and 4).6 13 14 15 16 17 18 19
 
Long-term outcomes and co-morbidities
Two patients received a stem-cell transplant: one an human leukocyte antigen DR 1 antigen–mismatch sibling-donor cord-blood transplant, and the other a 10/10 peripheral-blood stem-cell transplant from a matched unrelated donor. Both patients underwent transplantation at 20 to 21 months of age. Both achieved 100% donor chimerism 1 month after transplantation and remain transfusion-independent. Of the remaining seven patients who require regular transfusion every 3 to 6 weeks, only one shows moderate hepatic iron overload (case 2), and none have demonstrated infective complications. All five survivors older than 2 years received iron chelation therapy: three with deferasirox and two with deferiprone (one of whom has changed to deferoxamine owing to neutropenia). The median serum ferritin level was 1961 pmol/L (range, 411-5312 pmol/L). Endocrinopathies were noted in three patients: one had primary gonadal failure but did not require hormonal replacement therapy (case 1), one had hypogonadism requiring testosterone (case 5), and one (case 2) had partial adrenal insufficiency requiring stress-dose steroid but not regular hydrocortisone replacement (Tables 4 and 5).6 13 14 15 16 17 18 19
 

Table 5. Stem-cell transplantation details and outcome for haemoglobin Bart’s hydrops fetalis
 
Discussion
In Southeast Asia, BHFS is the most common cause of fetal hydrops.5 21 Because it is an autosomal recessive disorder, when both parents have two α-globin gene deletions in cis on chromosome 16 (each parent, --/αα), any offspring will have a 25% chance of having BHFS. In BHFS, haemoglobin tetramers of only gamma chains (γ4) is ineffective in erythropoiesis and oxygen delivery to tissues. The ensuing anaemia and tissue hypoxia interfere with organogenesis and development and also lead to fetal heart failure, extramedullary erythropoiesis, and maternal complications. In contrast to --FIL and --THAI gene deletions reported in the Philippines and Thailand, respectively, the --SEA or Southeast Asian deletion (the most common mutation in Hong Kong and demonstrated in all nine BHFS cases in this study) affects only the α-globin gene while sparing the embryonic ζ-globin gene, thus permitting production of Portland 1 (ζ2γ2) and Portland 2 (ζ2β2) haemoglobins. Hence, the affected fetus can survive through the antenatal and early neonatal period.
 
Pitfalls in prenatal screening and diagnosis
In Hong Kong, prenatal screening using a cut-off for maternal mean corpuscular volume of ≤80 fL and prenatal diagnosis using chorionic villus sampling, amniocentesis, and cordocentesis have been practised since 1983,22 23 24 25 thereby contributing to a decline in BHFS incidence for two decades. Despite public health endeavours in prenatal screening, however, BHFS babies continue to be born without prior prenatal diagnosis or parental counselling, resulting in adverse maternal and fetal outcomes.26 Causes of this phenomenon are principally two-fold: lack of proper antenatal screening and diagnosis, as well as improper implementation of screening or diagnostic procedures (Table 1). Better public education in both mainland China and Hong Kong would rectify the situation. Such education should stress the importance of early accurate prenatal diagnosis and the possible serious sequelae of late presentation or delayed diagnosis. Obstetricians should also note that normal paternal mean corpuscular volume does not exclude fetal BHFS because of the rare occurrence of maternal uniparental disomy (case 6)27 and non-paternity (possible in case 7).27 Routine mid-trimester scanning is imperative and diagnosis of BHFS should be considered if ultrasonography or clinical features are suggestive of BHFS (cardiomegaly, placentomegaly,18 28 and hydrops), regardless of the parents’ mean corpuscular volume.27 Placental thickness measurement allows early detection of BHFS in the first trimester, even before the appearance of hydropic features.18 28 If hydropic changes are detected, confirmation by cordocentesis and haemoglobin electrophoresis is warranted.
 
Counselling for parents in Hong Kong who opt to continue pregnancy
Suggested salient points of counselling for parents who opt for continuation of pregnancy are shown in the online supplementary Appendix. Once considered fatal, BHFS can now be detected and diagnosed antenatally, with survival being possible albeit not without complications. Detailed antenatal counselling for parents who are contemplating continuation of an affected pregnancy is crucial. Possible maternal-fetal complications, such as gestational hypertensive disorder and intrauterine growth restriction or death, should be addressed. On the basis of local experience, IUT is advised because there is a risk of miscarriage or intrauterine infection (case 9). Multiple IUTs may be indicated if fetal anaemia is suggested by serial Doppler ultrasonography (peak systolic velocity of the middle cerebral artery of >1.5 multiples of the median). Premature delivery and perinatal respiratory depression are often encountered. Neonatal intensive care unit admission and intubation are anticipated from local experience. Inotropic support may be required in the early neonatal period, as well as cardiopulmonary support, such as mechanical ventilation, surfactant treatment, high frequency oscillation ventilation, and nitric oxide inhalation for persistent pulmonary hypertension of the newborn. Exchange transfusion is often performed postnatally, in most cases within the first 24 hours of life.
 
Congenital malformations are often encountered, the most common being genitourinary and musculoskeletal defects, but are usually amenable to surgical correction. It is worth noting that all male babies in our local cohort displayed hypospadias. Two-thirds of our patient cohort showed growth retardation, global developmental delay, and/or long-term residual neurological deficits. These findings are comparable to those from an international case series29 and an overseas case report.11 Lifelong hypertransfusions every 4 to 6 weeks and iron chelation are expected for BHFS survivors. Haematopoietic stem-cell transplantation is a possible cure and has been successful in some local cases (Table 3). Nevertheless, transplant-related mortality and morbidity should not be overlooked. The proposal that parents produce a subsequent sibling to serve as a ‘saviour baby’ and potential donor is feasible but raises ethical concerns. Careful consideration and proper parental counselling are necessary.
 
Comparison of outcomes and morbidities between local and international cohorts
Globally, 69 survivors are reported in the international BHFS registry29 with our local cohort (n = 9) contributing about one-seventh of cases. Approximately two-thirds of all cases used IUT29 (41/69; 59%), which is similar to the proportion of local cases (5/9; 56%). Globally29 and locally, most infants were delivered prematurely (respectively, 47/66; 71% and 7/9; 78%). Approximately one-fifth (14/69) of all BHFS survivors underwent stem-cell transplantation,29 again similar to our local situation (2/9). Congenital anomalies were present in all of the local patients, compared with two-thirds (37/55; 64%) worldwide,29 although urogenital and limb defects remained the most common. Nearly half (26/55; 47%) of global BHFS survivors demonstrated various degrees of transient or permanent neurodevelopmental impairment,29 in contrast to two-thirds of our cohort. Sohan et al (2002)30 described the first BHFS survivor in the United Kingdom: a 38-week-old baby girl of Hong Kong parents, who was referred at 21 weeks of gestation for hydrops fetalis, received serial IUT and had BHFS antenatally diagnosed. Two exchange transfusions were performed postnatally and the baby was discharged on day 6 of life followed by transfusions every 4 to 5 weeks. At the time of that publication, she was 18 months old and had normal growth and development apart from bilateral transverse palmar creases and a mild lobster-claw deformity of the right foot.30
 
Strengths, limitations, and recommendations
This is the first territory-wide multicentre retrospective study to describe in depth the basic demographic characteristics and perinatal and long-term outcomes of BHFS survivors in Hong Kong over the past two decades or so. It also explores the reasons and cultural circumstances for which parents opted to continue the pregnancy despite public health endeavours to promote antenatal screening. Furthermore, it adds two more local cases to those submitted and recently published by the BHFS International Consortium.29 However, the small sample size precludes statistical analyses, and the data covers only the eight local public hospitals with haematology units and a period of 20 years (as the cut-off age in Hong Kong for paediatric care is 20 years and the Clinical Data Analysis and Reporting System began only in 1996). Survivors beyond 20 years of age and patients who defaulted follow-up to receive long-term medical care in the private sector or overseas were excluded from this study. In addition, the numbers of abortions and stillbirths, as well as BHFS babies with early neonatal death were not studied. Multidisciplinary collaboration between obstetricians, paediatric haematologists, and adult-care physicians at all local hospitals and concerted efforts in data collection and analysis are recommended. With the establishment of the Hong Kong Children’s Hospital in 2018, it is hoped that a standardised protocol of management and counselling can be compiled, data collection streamlined, and analysis facilitated for future research.
 
To conclude, survival of patients with BHFS is possible but not without short- and long-term complications. Local epidemiology of BHFS survivors is similar to that reported for an international registry. Detailed antenatal counselling of parents with a non-judgemental attitude and cautious optimism are imperative.
 
Supplementary information
Online supplementary information (Appendix) is available for this article at www.hkmj.org.
 
Acknowledgements
We thank the Hong Kong Paediatric Haematology and Oncology Study Group and the paediatric haematologists from the eight participating hospitals for patient management, case contribution, and data cross-checking.
 
Declaration
The authors have no conflicts of interest to disclose.
 
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