Understanding the Outpatient Medication Use and Spending of Cognitively Impaired Older Adults Under Changing Medicare Part D Policy

Between 2011 and 2020, the Affordable Care Act progressively closed the Medicare Part D coverage gap, reducing coinsurance from 100% to 25% to alleviate financial burdens and improve prescription drug access. Individuals with cognitive impairment face particularly high drug costs and are at greater risk for medication discontinuation. Furthermore, adherence is essential in this population for managing their disease and comorbidities to reduce their healthcare use and expenditures. We evaluated the effect of reduced coinsurance on out-ofpocket (OOP) costs and medication use for beneficiaries with cognitive impairment, as well as the association between medication adherence and inpatient (IP) and emergency department (ED) related healthcare costs and visits.