Polypharmacy associated with low functional capacity in older adults: results from the SHIP-Brazil Study

Abstract Objective To investigate the association between polypharmacy and low functional capacity among older adults residing in southern Brazil. Method This cross-sectional observational study involved 511 older adults participating in the Study of Health in Pomerode (SHIP-Brazil) study. A structured questionnaire interview was conducted, including sociodemographic, behavioral, general health, and healthcare variables. Functional capacity was assessed using a 0-to-100 scale and quartiles based on the SF- 36 questionnaire. The association between polypharmacy (five or more medications) and low functional capacity (25th percentile or lower) was estimated using logistic regression. Results Among the participants, 48.3% used five or more medications. The median functional capacity was 65 (IQR 40–85). A negative correlation was observed between the functional capacity scale and the number of medications (rho = -0.3068; p > 0.001). The likelihood of having low functional capacity was 2.8 times higher (95% CI 1.8–4.1) among those consuming five or more medications compared to those consuming four or fewer. This association remained significant across all adjusted models, with the greatest reductions observed for clinical (OR = 1.6; 95% CI 1.1–2.6) and healthcare-related variables (OR = 1.8; 95% CI 1.2–2.9). Conclusion There is an association between polypharmacy and low functional capacity, even after adjusting for socioeconomic, lifestyle, general health, and healthcare-related factors. It is essential to implement health promotion actions targeted at the population aged 60 years or older who use medications, ensuring effective and safe treatment while preventing low functional capacity.