Prevalence and predictors of medication non-adherence among older community-dwelling people with chronic disease in Singapore.

Aims: To determine the prevalence and predictors of medication non-adherence among older community-dwelling people with at least one chronic disease in Singapore.

Design: A single-centre cross-sectional study.

Methods: The study was conducted in the largest tertiary public hospital in Singapore between May 2019 and December 2019. The community nurses of the hospital recruited a total of 400 community-dwelling older people aged ≥60 years old, who were diagnosed with at least one chronic disease and prescribed with at least one long-term medication. Medication non-adherence was assessed using the self-report 5-item Medication Adherence Report Scale, operationalized as a score of <25. A list of potential factors of medication non-adherence was structured based on the World Health Organization five-domain framework and collected using a self-report questionnaire.

Results: Sixty percent (n = 240) of our participants were non-adherent to their medication regime. Older people who smoked (OR 2.89, 95% CI 1.14-7.33), perceived their medication regime as being complicated (OR 2.54, 95% CI 1.26-5.13), felt dissatisfied with their regime (OR 2.50, 95% CI 1.17-5.31), did not know the purpose of all their medications (OR 2.56, 95% CI 1.42-4.63) and experienced side effects (OR 3.32, 95% CI 1.14-9.67) were found to be predictive of medication non-adherence.

Conclusion: Medication adherence was found to be poor in community-dwelling older people in Singapore. The predictors identified in this study can help guide healthcare professionals in identifying older people who are at risk of medication non-adherence and inform the development of interventions to improve adherence.

Impact: Medication non-adherence, especially in the older population with chronic diseases, constitutes a serious problem as it undermines the efforts to reduce morbidity and mortality associated with the underlying chronic diseases. To improve adherence, our findings propose the importance of assessing the older person's treatment satisfaction, which includes examining the aspects of side effects, effectiveness and convenience. Additionally, we highlight the need to address the older person's medication knowledge deficit.