title: The effect of Medicare Part D coverage on drug use and cost sharing among seniors without prior drug benefits.
abstract: This study evaluates the effect of Medicare Part D among seniors who previously lacked drug coverage, using time-trend analyses of patient-level dispensing data from three pharmacy chains. Of 114,766 seniors without drug benefits, 55 percent initiated drug insurance under Part D. After the penalty-free Part D enrollment period, use of statins, clopidogrel, and proton pump inhibitors stabilized at levels ranging from 11 percent to 37 percent above the trend that would have been expected if Part D had not been implemented. Patients reaching the Part D coverage gap (12 percent) experienced a decrease in essential medication use ranging from 5.7 percentage points per month for warfarin to 6.3 percentage points for statins.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women's Hospital in Boston, Massachusetts, USA. sschneeweiss@partners.org
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schneeweiss
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Patrick
authors.forename: Alex
authors.initials: A
authors.lastname: Pedan
authors.forename: Laleh
authors.initials: L
authors.lastname: Varasteh
authors.forename: Raisa
authors.initials: R
authors.lastname: Levin
authors.forename: Nan
authors.initials: N
authors.lastname: Liu
authors.forename: William H
authors.initials: WH
authors.lastname: Shrank
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017047:Cost Sharing; D005260:Female; D006299:Health Services for the Aged / Q000191:economics*; D006801:Humans; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data*; D054524:Medicare Part D / Q000706:statistics & numerical data*; D014481:United States