The effect of Medicare Part D coverage on drug use and cost sharing among seniors without prior drug benefits.
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.
Schneeweiss
Sebastian
S
Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women's Hospital in Boston, Massachusetts, USA. sschneeweiss@partners.org
Patrick
Amanda R
AR
Pedan
Alex
A
Varasteh
Laleh
L
Levin
Raisa
R
Liu
Nan
N
Shrank
William H
WH
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