Factors associated with polypharmacy and inappropriate medication use among older people: a longitudinal study of the Urban Health Centres Europe (UHCE)

Abstract Background: Polypharmacy and inappropriate medication use among older people is associated with adverse health consequences due to drug-drug interactions, drug-disease interactions, and adverse drug effects. The aim of this study is to assess the factors that are associated with polypharmacy and inappropriate medication use among community-dwelling older people in Europe.Method: This longitudinal study used baseline and follow-up data from 1791 participants of the Urban Health Center European project in five European countries. We studied factors in the domains (a) demographic characteristics, (b) lifestyle and nutrition, and (c) health and health care use, Hierarchical logistic regression models were used to examine the factors associated with polypharmacy and inappropriate medication.Results: Mean age was 79.6 years (SD±5.6 years); 60.8% were women; 45.2% had polypharmacy, and 41.8% had a high risk of inappropriate medication use. Participants who were women had higher odds of both having polypharmacy (OR=0.55;95%CI:0.42-0.72) and inappropriate medication use (OR=0.50;95%CI:0.39-0.65). Participants with a migration background (OR=1.67;95%CI:1.08-2.59), overweight (OR=1.37; 95%CI:1.04-1.79) and obesity (OR=1.78;95%CI:1.26-2.51) compared to ‘normal weight’, with lower physical HRQoL (OR=0.96, 95%CI:0.95-0.98), multi-morbidity (OR=3.73, 95%CI:2.18-6.37), frailty (OR=1.69, 95%CI:1.24-2.30), visited outpatient services (OR=1.77, 95%CI: 1.09-2.88) had higher odds of having polypharmacy. The associations with inappropriate medication use were similar.Conclusions: Multiple factors in the domains of demography, lifestyle, nutrition, and health care use are associated with polypharmacy and inappropriate medication use. These provide starting points to improve interventions to reduce polypharmacy and inappropriate medication use. In the meantime, health professionals can apply these insights to identify subgroups of patients are at a high risk of polypharmacy and inappropriate medication use. Trial registration: The intervention of the UHCE project was registered in the ISRCTN registry as ISRCTN52788952. The date of registration is 13/03/2017.