Out-of-hospital cardiac arrest is a public health problem and leads to the highest proportion of deaths in many parts of the world.1 2 According to the American Heart Association (AHA), in the US and Canada, approximately 350 000 people per year suffer out-of-hospital cardiac arrests for which cardiopulmonary resuscitation (CPR) is attempted.1 3 4 In Hong Kong, although no such direct epidemiological information can be referred to, more than 1000 persons are believed to die suddenly and unexpectedly each year; many of which are presumed to be primarily due to cardiac arrests.5

For those who endure sudden cardiac arrests, early, high-quality CPR can greatly improve chances of survival.6 7 Nowadays, the importance of CPR is well recognised and emphasised. Accordingly, the AHA even recommended that CPR training and familiarisation with automated external defibrillators (AEDs) should be included in secondary school curricula.8 Thus, equipping the public with such skills becomes one of the essential strategies to increase the success of CPR for cardiac arrest victims.

In recent years, studies have been conducted to examine the knowledge and attitude of the public regarding CPR. In general, people had poor knowledge on this subject and the proportion of the public who had received the CPR training was low.9 10 11 12 Besides, many individuals did not want to perform cardiac compression with mouth-to-mouth ventilation, due to fear of acquiring transmitted diseases.13 These factors are likely to limit the numbers of bystander CPRs carried out and contribute to the low survival rates from out-of-hospital cardiac arrests. A local study showed that for out-of-hospital cardiac arrests, the frequency of bystander CPR was only about 15.7% and the survival rate to eventual discharge from hospital was as low as 1.3% in Hong Kong.10

To identify effective measures to promote CPR, the current situation should be evaluated. This study aimed to explore the Hong Kong public’s knowledge and attitudes about CPR. Its findings could inform the community regarding preferences to perform bystander CPR and more importantly it could indicate directions for future training.

This was a cross-sectional population-based survey. The study population comprised the Chinese Hong Kong residents aged 15 to 64 years, who speak Cantonese in domestic households. Anonymous telephone interviews using a structured questionnaire were conducted and launched in the Telephone Survey Research Laboratory of the Hong Kong Institute of Asia-Pacific Studies of The Chinese University of Hong Kong. By using the Computer Assisted Telephone Interviewing system, telephone numbers were randomly selected from up-to-date residential telephone directories that covered over 95% of Hong Kong households. The interviews were conducted between 6:15 pm and 10:15 pm, to avoid over-representing the non-working population. For households with more than one eligible member, the one whose birthday was closest to the interview date was invited to join the study. At least three attempts were made to contact individuals in any given household. Such attempts were made at different times of the day and/or different days of the week, to avoid being labelled a non-contact status (with an assigned number) so as to ensure that survey results were not biased due to high non-contact/non-response rates. Eligible respondents were briefed about the study and verbal consent was sought. The study was approved by the Survey and Behavioural Research Ethics Committee of The Chinese University of Hong Kong.

According to a previous study,11 12% of the population had received CPR training. Owing to continuing efforts and CPR promotion programmes/campaigns by different associations and organisations in recent years, it was expected that around 20% of the study population had probably received prior CPR training. Depending on the possible prevalence of subjects with prior CPR training (ranging from 18 to 22%), it was estimated that 883 to 1025 subjects would be sufficient to estimate knowledge and attitudes with a margin of error of ± 2.5% at 5% level of significance. The sample size calculation was performed using PASS 11 (NCSS, Kaysville [UT], US). Thus, we aimed to recruit over 1000 subjects for this study.

In this study we used a structured questionnaire, which took about 5 to 10 minutes to complete, and was developed in January 2010 (Appendix). It was based on the 2005 AHA Guidelines for CPR and Emergency Cardiovascular Care,14 Basic Life Support for health care providers,15 and a review of the relevant literature.11 12 It consisted of three sections. The first entailed questions on demographics, including age, gender, education level, occupation, family history of heart disease, and ischaemic heart disease risk factors. The second entailed questions about previous CPR training. The third entailed questions on attitudes and knowledge regarding CPR. To evaluate respondents’ relevant attitudes and knowledge, questions were included about: willingness to perform CPR (2 items), the basic knowledge related to a victim’s response (1 item), management of airway (2 items), breathing (2 items), circulation (2 items), and AED usage (1 item). The anticipated answers for the CPR knowledge questions (victim’s response, management of airway, breathing, and circulation) were consistent with information in the latest AHA guidelines (2005 version). Content validity was established by an expert panel including four doctors and six nurses who were either AHA Basic Life Support providers or instructors. The content validity index rating item’s relevance to the underlying construct was 0.96.

Data were categorised and presented in frequencies (percentages). Univariate comparisons on demographics and ischaemic heart disease risk factors among those with and without CPR training were conducted, using Pearson Chi squared or Fisher’s exact tests, as appropriate. Logistic regression analysis was used to identify demographics and ischaemic heart disease risk factors (Table 1) that were associated with CPR training. Variables with a P value of <0.25 in the univariate analysis were selected for use in the stepwise multivariate logistic regression analysis, to delineate factors independently associated with CPR training.16

Logistic regression models were also employed to compare subjects with and without CPR training with respect to various outcome variables (attitude and knowledge about CPR), after adjustment for demographics and coronary heart disease risk factors. A ‘two-block stepwise’ logistic regression modelling approach was used to make adjusted comparisons of the two groups. The grouping factor (CPR training: Yes/No) was first entered into logistic regression model and then the demographics and ischaemic heart disease risk factors (Table 1) were entered in another block with stepwise selection. In the final model, the adjusted odds ratio (OR) to compare those with and without CPR training (reference group) was derived, taking account of demographics and ischaemic heart disease risk factors. All statistical analyses were conducted using SPSS 19.0 (Windows version 19.0; SPSS Inc, Chicago [IL], US) with two-sided tests; a P value of <0.05 was considered statistically significant.

In this study, 2703 phone calls were not picked up after three attempts, and 5669 calls were picked up but 2735 calls were disconnected immediately after knowing the purpose of the calls. A total of 2188 eligible respondents were identified, 1175 refused to participate. Finally, 1013 interviews were conducted (response rate, 46%). The demographics and ischaemic heart disease risk factors of these respondents are shown in Table 1.

Among the 1013 respondents, only 214 (21%) reported that they had received CPR training; the majority (72%, n=154) of whom had had their latest training more than 2 years earlier. A large proportion (63%, n=134) of the trained respondents received their training via the Hong Kong St John Ambulance (49%, n=104) and the Hong Kong Red Cross (14%, n=30). Another 35 (16%) participants had their training via their companies or workplaces. Their main reasons for taking CPR training were ‘job requirement’ (48%, n=102) and ‘personal interest’ (42%, n=90). For those who did not take CPR training (n=799), most of them (74%, n=589) claimed that they would not consider participating in CPR training in the future. Reasons for not taking CPR training could be multiple, and included ‘no time’ (41%, n=241), ‘not necessary’ (26%, n=156), and ‘not interested’ (19%, n=110). In addition, 104 (18%) participants picked ‘unable to learn CPR because of their low education level or being too old’.

Demographic and ischaemic heart disease risk factors listed in Table 1 with a P value of <0.25 in the univariate analysis were selected as candidate variables for multivariate stepwise logistic regression.16 Among them, age, education level, full-time working status, occupation, having dyslipidaemia and hypertension were associated with having CPR training in the univariate analysis. However, only having a full-time job (OR=2.2; 95% confidence interval [CI], 1.6-3.1; P<0.001), middle level education—Form 4-7/technical institute (OR=2.3; 95% CI, 1.5-3.6; P<0.001), and a high level of education—college or higher (OR=2.7; 95% CI, 1.7-4.2; P<0.001), were significantly associated with having CPR training in the multivariate analysis. Notably, having a low education level—Form 3 or below—was not significantly associated with such training (Table 2).

As shown in Table 3, the ratio of respondents with and without training willing to attempt CPR on family members at home was 72% vs 45% (P<0.001) and on strangers in the street was 42% vs 15% (P<0.001). Logistic regression analysis revealed that after adjusting for potentially confounding demographic and ischaemic heart disease risk factors, those with CPR training were also more likely to attempt CPR at home (OR=3.3; 95% CI, 2.4-4.6; P<0.001) and in the street (OR=4.3; 95% CI, 3.1-6.1; P<0.001) in emergencies (Table 3).

Regarding knowledge on CPR, trained respondents were more likely to give correct responses to each of the eight knowledge questions (all P<0.001). After adjusting for potential confounding demographic and ischaemic heart disease risk factors, logistic regression showed that the trained group was significantly more likely to give five or more appropriate responses to the eight knowledge items when compared with those without such training (OR=19.8; 95% CI, 11.4-34.4; P<0.001; Table 3). Although the trained respondents achieved higher scores on CPR knowledge (median=3) than those who were untrained (median=1), the overall CPR knowledge level of the respondents was low (median=1). Among all the 1013 respondents, only four (0.4%) answered all the questions correctly (score=8), which also represented 1.9% of those who had received CPR training (Table 4).

The present study showed that 21% of the respondents had received CPR training, which was higher than in a previous local study reporting 12%.11 Our rate was comparable to data reported from elsewhere (27% in New Zealand and 28% in Ireland),17 18 but much lower than in reports from Australia (58%),19 Poland (75%),20 and Washington (79%).21 Therefore, though the trend for CPR training in Hong Kong seems to be increasing, it seems far from sufficient, and the majority had received their training more than 2 years earlier. Although it is commonly believed that performing CPR without 100% accuracy is better than doing nothing, whether our respondents could perform appropriate CPR in an emergency was questionable. In our cohort, skills appeared to have deteriorated with time. One study suggested that 6-monthly reinstruction was needed to maintain adequate CPR skills22; the 2-year intervals noted in this study were much longer than what has been suggested. Thus, after their first training, it is suggested that individuals should attend refresher courses. Moreover, the training institutions should pay more attention to remind the trainees on the need for such reinstruction and updates.

The main reasons of taking CPR training were “job requirement” and “personal interest”, which were similar to reasons given in a previous study from Ireland.18 Therefore, the workplace might be considered a preferred place to conduct CPR training in conjunction with government and non-government organisations; in Hong Kong, these include St John Ambulance, the Hong Kong Red Cross, and the Auxiliary Medical Services. In fact, promoting CPR training in workplace seems an important strategy, as 16% of trained respondents in this study had already received such training in their workplaces, and this was also in line with the results of a study by Jennings et al.18

In this study, most non-trained respondents would not consider receiving CPR training, giving the following reasons: “no time”, “not necessary”, or “not interested”. Lack of time for CPR training is a common reason reported in different studies.11 23 24 To address this problem, self-instruction, such as via video or internet training, may be considered. Studies have shown that video self-instruction training was as good as traditional classroom training,25 26 which is not only cost-effective but also flexible compared to formal classroom training. In addition, as recommended by the AHA,8 CPR training could be incorporated into general education in secondary schools. Several studies have investigated knowledge and attitude towards CPR training, its feasibility and the impact of CPR or life-supporting first-aid training in primary and secondary schools in various countries (Austria, Japan, and Norway) and reported a positive experience.27 28 29 Either as part of the regular curriculum, as mandatory courses, or as an elective extra-curricular activity, it could be beneficial to the students and the general public. By providing students with CPR training, the first part of the chain of survival in out-of-hospital cardiac arrest could be enhanced for future generations, and increase survival after sudden cardiac arrest. To successfully carry out such a health and education policy, the Hong Kong SAR Government can learn from other Asian countries like Japan and Singapore, which have already gained experience in CPR education for secondary schools.

Those with full-time jobs and with higher levels of education were more likely to attend CPR training, which corresponded with the results of previous studies.11 18 Not surprisingly 48% of respondents in the present study were required to attend their CPR training in connection with their jobs, while 18% believed that they were unable to learn as they were too old or their level of education was too low. Accordingly, this misunderstanding about CPR needs correcting, and certainly CPR training should be made available to those who are not employed. Community centres could be used as possible teaching venues to promote CPR, in conjunction with the Hong Kong SAR Government and other health care organisations (Hospital Authority, Hong Kong Red Cross, and St John Ambulance). These health-related organisations could play critical roles in publicising the importance of CPR, and provide accessible trainings for the public. Encouragingly, the Resuscitation Council of Hong Kong was established in 2012, and has the power to promote high standards of training and public awareness on resuscitation.

In this study, respondents with CPR training were more willing to perform it at home and in the street (under emergency situations), presumably as they had acquired enough knowledge and skills to generate confidence and courage. The powerful impact of CPR training on saving lives should never be underestimated. Although only 15% of the respondents without CPR training would like to save others’ lives, nearly half of them (45%) expressed willingness to perform CPR for their family members if needed. The intimate relationship among family members may be the motivation in such cases. According to the AHA, 80% of sudden cardiac arrests happen at home.7 Therefore, it makes sense to exploit intimate emotions to facilitate and publicise the CPR training, especially for those with vulnerable members in their family.

In this study, the overall level of CPR knowledge of the respondents was very low, with a median of one correct answer out of eight questions, which was in agreement with previous studies.11 20 Knowledge was particularly weak related to the compression-to-ventilation ratio and appropriate number of cardiac compressions per minute. This could be because 79% of the respondents had not received any CPR training, whereas 72% out of the 214 who had, recalled receiving it more than 2 years earlier and 51% had received it more than 5 years earlier. The AHA recommends its frequently revised CPR guidelines based on rigorous scientific evidence and the consensus opinions of experts. Using a compression-to-ventilation ratio of 30:2 during CPR for victims of all ages was a major update in 2005.30 In addition, the sequence of ‘A-B-C’ (Airway, Breathing, Chest compression) was changed to ‘C-A-B’ (Chest compression, Airway, Breathing) in the 2010 Guidelines.30 Therefore, knowledge about up-to-date guidelines is likely to be most rewarding.

This survey did not explore why people refused to perform CPR, which could be crucial for raising bystander CPR rates in Hong Kong. As indicated in one study from Japan, people had fear of contracting transmitted diseases through mouth-to-mouth ventilations.13 Legal liability could be another concern. Therefore, public education and laws to protect CPR providers appear necessary, for which Good Samaritan laws need to be enacted. Certainly, the reasons why Hong Kong citizens opt not to undertake CPR warrant future surveys.

Knowledge of CPR in the Hong Kong public is still poor. The percentage of citizens that have had CPR training is relatively low. Unwillingness to perform CPR is particularly common, especially among those who have not received any CPR training. Government and non-government organisations need to promote educational activities and explore diverse approaches to reinforce and refresh the content of training. Government needs to increase public awareness of CPR and enact laws to protect bystanders undertaking CPR. Incorporating CPR training into the secondary school and college curricula has also been suggested.

The authors declare that there is no conflict of interest.

The study was supported by the Nethersole School of Nursing, Cardiovascular and Acute Care Research Group Funding.

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