Drug utilization and polypharmacy in an Italian elderly population : the EPIFARM-elderly project

Objective: To investigate the prescribing patterns and the prevalence of polypharmacy in community-dwelling elderly people, and to analyze the association of chronic medications and number of drug prescriptions with age and sex. Methods: All prescriptions for people aged 65 years or older reimbursed by the Italian National Health Service (NHS) and dispensed by retail pharmacies of the 15 local health units (LHU) in the Lombardy Region during 2005 were analyzed. Logistic regression analysis was used to assess the association between drug prescription (overall, chronic drugs, and polypharmacy) and age, sex, and LHU of residence. Results: Eighty-eight percent of the 1767239 analyzed elderly received at least one drug prescription. The overall prescription rate was slightly higher for women than men (odds ratio [OR] 1.20; 95%CI 1.19-1.21). Seventy-six percent of the elderly received at least one chronic drug, 46% were exposed to polypharmacy, and 20% to chronic polypharmacy. At multivariate analysis, age and LHU residence of the elderly were the main determinants of drug exposure. A significant correlation was found between the overall prescription prevalence rate and exposure to chronic drugs and to chronic polypharmacy (rs=0.79, p<0.0005 and rs=0.84, p<0.0001, respectively). Conclusions: Our findings indicate that age and LHU residence of the elderly are the main determinants of drug prescribing, and there is evidence of a significant correlation between the overall prescription prevalence rate and exposure to chronic drugs and to chronic polypharmacy.