Multimorbidity, polypharmacy and primary prevention in community-dwelling adults in Quebec: a cross-sectional study.

backgroundPolypharmacy carries the risk of adverse events, especially in people with multimorbidity.

objectiveTo investigate the prevalence of polypharmacy in community-dwelling adults, the association of multimorbidity with polypharmacy and the use of medications for primary prevention.

methodsCross-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. Multimorbidity was defined as the presence of three or more chronic diseases and polypharmacy as self-reported concurrent use of five or more medications. Primary prevention was conceptualized as the use of statin or low-dose antiplatelets without a reported diagnostic of cardiovascular disease.

resultsMean age 56.7 ± 11.6, 62.5% female, 30.3% had multimorbidity, 31.9% had polypharmacy (n = 971). The most common drugs used were statins, renin-angiotensin system inhibitors and psychotropics. Compared to participants without any chronic disease, the adjusted odds ratios (ORs) for having polypharmacy were 2.78 [95% confidence interval (CI): 1.23-6.28] in those with one chronic disease, 8.88 (95% CI: 4.06-19.20) in those with two chronic diseases and 25.31 (95% CI: 11.77-54.41) in those with three or more chronic diseases, P < 0.001. In participants without history of cardiovascular diseases, 16.2% were using antiplatelets and 28.5% were using statins. Multimorbidity was associated with increased likelihood of using antiplatelets (adjusted OR: 2.98, 95% CI: 1.98-4.48, P < 0.001) and statins (adjusted OR: 3.76, 95% CI: 2.63-5.37, P < 0.001) for primary prevention.

conclusionThere was a high prevalence of polypharmacy in community-dwelling adults in Quebec and a strong association with multimorbidity. The use of medications for primary prevention may contribute to polypharmacy and raise questions about safety.