Polypharmacy among the elderly: a population-based study.

Objective: To investigate polypharmacy among the elderly living in the urban area of Florianopolis, in the state of Santa Catarina, Brazil, estimating the prevalence and associated factors. Methods: This is a cross-sectional population-based study with a sample of 1,705 individuals aged 60 years old or older, between 2009 and 2010. The dependent variable was polypharmacy (defined as "use of five or more medications"). The following exploratory variables were utilized: sociodemographic data, use of health services and self-rated health status. Prevalence ratios (PR) were estimated by multivariate analysis using the Poisson regression. Results: The mean for the medications used by the elderly population was 3.8 (ranging from 0 to 28). The prevalence of polypharmacy was 32%, with 95% confidence interval (95% CI) 29.8 - 34.3. The characteristics presenting a positive association with polypharmacy were: female gender (PR = 1.27; 95%CI 1.03 - 1.57), increasing age (PR = 1.38; 95% CI 1.08 - 1.77), negative self-rated health status (PR = 1.99; 95% CI 1.59 - 2.48) and medical appointments in the 3 months prior to the interview (PR = 1.89; 95% CI 1.53 - 2.32). The groups of medication most utilized by the elderly individuals in polypharmacy were those indicated for the cardiovascular system, digestive tract and metabolism, as well as the nervous system. Conclusion: The pattern of medication use among this elderly population is within the national average. The prevalence of polypharmacy and the characteristics associated with it were similar to those found in other regions of Brazil.