Polypharmacy in the general population of a Northern Italian area: analysis of administrative data

Abstract

Introduction: The aim of this study was to estimate the prevalence and assess patient-related determinants of polypharmacy in the general population of the Italian area around Udine.

Materials and methods: A retrospective cohort study was conducted using administrative databases: drug prescriptions, hospital discharges, ambulatory care prescriptions, exemptions from medical charges. Various definitions of polypharmacy were adopted (co-prescription of multiple medications, use of multiple medications for overlapping time periods). The role of patient’s characteristics on polypharmacy was assessed through regression analyses.

Results: In 2017, 63.7% of the general population received at least one drug prescription. 25,218 persons were co-prescribed ≥5 medications at least once. The prevalence of co-prescriptions among persons ≥65 years was 31.7%. 20,793 persons used ≥60 DDDs of ≥5 medications. The prevalence of all these phenomena was much higher in the elderly than in children and adults. The number of comorbidities significantly affected all types of polypharmacy.

Conclusions: In this area, the prevalence of polypharmacy is alarming, particularly among the elderly. Age and comorbidities significantly affect the risk. Further research will aim at evaluating the health effects of polyphamacy.