Use of potentially inappropriate medication and polypharmacy in elderly: a repeated cross-sectional study

Background Potential inappropriate medications (PIM) have an increased risk for adverse drug reactions (ADR) in an elderly population. With increasing age, multimorbidity is growing along with the use of medications. For several years, polypharmacy has been found to increase in western societies. Polypharmacy is associated with an increased risk of ADR. In this study, we analysed the prevalence of PIM in an elderly population and in different strata of the variables age, gender, number of chronic conditions and polypharmacy and how that prevalence changed over time. Methods This is a registry based repeated cross-sectional study including two cohorts included. Individuals aged 75 or older listed at a primary care center in Blekinge on the 31 of March 2011 (cohort 1) or on the 31 of December 2013 (cohort 2) were included in the respective cohorts. Using a chi2 test, the two cohorts were compared on the variables age, gender, number of chronic conditions and polypharmacy. Use of five or more medications at the same time was the definition for polypharmacy. Results Use of PIM decreased from 10.60% to 7.04% (p-value <0.001) between 2011 and 2013, while prevalence of five to seven chronic conditions increased from 20.55% to 23.66% (p-value <0.001). Use of PIM decreased in all strata of the variables age, gender number of chronic conditions and polypharmacy. Except for age 80 to ≤ 85 and males, where it increased, prevalence of polypharmacy was stable in all strata of the variables. Conclusions Use of potentially inappropriate medications had decreased in all variables between 2011 and 2013. Polypharmacy does not increase significantly compared to the rest of the population.