Grant: Travel Awards - Institute Community Support

Context. Polypharmacy carries the risk of adverse events due to drug-drug and drug-disease interactions, especially in people with multimorbidity (MM) and raises concerns about safety. Objective. To investigate the prevalence of polypharmacy in community-dwelling adults in Quebec, and the impact of MM on polypharmacy and patterns of drug use in this population. Design. Cross-sectional analysis of the follow-up data from the Program of Research on the Evolution of a Cohort Investigating Health System Effects (PRECISE) in Quebec, Canada. Setting. Community-dwellers aged 18 or older. MM defined as having at least 3 chronic diseases from a list of 14 self-reported chronic diseases. Outcome measures. Polypharmacy (self-reported concurrent use of at least 5 medications) Results. Mean age 57, 64.8% female, 32.3% had MM (N=1454). The prevalence of polypharmacy was 34.3% in all participants (67.4% in participants with MM, 18.4% in those without MM). Compared to participants without any chronic disease, the adjusted odds ratios for having polypharmacy were 1.6 (95%CI 0.9-3.0) in those with 1 chronic disease, 5.6 (95%CI 3.2-9.8) in those with at least 2 chronic diseases, and 18.5 (95%CI 10.7-32.2) in those with at least 3 chronic diseases. The most common medications in participants with MM were statins (57.2%), renin-angiotensin inhibitors (50.9%), and antiplatelets (41.3%); while in participants without MM the most common were renin-angiotensin inhibitors (21.9%), statins (21.2%), vitamins and supplements (21.0%). In this study, 17.7% of participants without a history of cardiovascular diseases were using antiplatelets and and 28.5% were using statins. Conclusions. There was a high prevalence of polypharmacy in community-dwelling adults in Quebec. Multimorbidity significantly increased the risk of polypharmacy. The use of a medication for primary prevention may contribute to polypharmacy and raise questions about safety to be investigated further.