Drug non-adherence and associated risk factors among Chinese geriatric patients in Hong Kong

PW Lam, CM Lum, MF Leung
Specialty Outpatient Department, United Christian Hospital, Kwun Tong, Hong Kong

OBJECTIVES. To study the prevalence of drug non-adherence among Chinese elderly people and its associated risk factors.

DESIGN. Cross-sectional survey.

SETTING. Medical and Geriatrics specialist out-patient clinic in a regional hospital.

PATIENTS. Elderly patients (≥65 years) with chronic diseases requiring regular medications were selected by systematic sampling.

MAIN OUTCOME MEASURES. Drug non-adherence; potential risk factors studied include patients' factors, availability of assistance, and prescription factors.

RESULTS. Two hundred and nine elders participated with 84% response rate. Estimated mean prevalence rate of drug non-adherence was 37% (standard deviation, 7%). The risk factors for drug non-adherence were: (1) self-perceived adverse drug effects (odds ratio=2.5; 95% confidence interval, 1.2-5.2; P=0.017); (2) use of respiratory drugs (2.7; 1.0-7.5; P=0.048); (3) complicated drug regimens (7.4; 3.2-16.9; P<0.001); and (4) necessity to cut tablets (4.8; 2.1-10.7; P<0.001). Presence of caregiver/community nursing services assistance to pack medication (odds ratio=0.2; 95% confidence interval, 0.1-0.5; P=0.001), and the use of medication boxes (0.5; 0.3-1.0; P=0.050) were found to be the protective factors against drug non-adherence.

CONCLUSION. Drug non-adherence is an important concern in patient management. Medication regimen should be simplified as far as possible, in particular to avoid cutting pills or use of different dosage at different timing. Patients receiving drugs for respiratory diseases should be the first target group for intervention. Patients should be encouraged to voice out their perceived adverse drug effects.

Hong Kong Med J 2007;13:284-92

Key words: Aged; Chinese; Patient compliance; Prescriptions, drug; Risk factors