Medication adherence in community-dwelling older people exposed to chronic polypharmacy

BACKGROUND: To evaluate medication adherence and associated factors of seven of the most common drug classes prescribed to community-dwelling older people. METHODS: This is a retrospective cohort study on medication adherence in community-dwelling older people (65-94 years old) on chronic polypharmacy and recorded from 2013 to 2015 in the administrative database of the Lombardy region (Northern Italy). Adherence was assessed for diabetic drugs, antithrombotic agents, drugs acting on the renin-angiotensin system, statins, bisphosphonates, antidepressants and drugs for obstructive airway diseases by calculating the medication possession ratio (MPR). Patients were then divided in fully (MPR ≥80%), partially (40%≤MPR<80%) and poorly adherent (10%