Has Medicare Part D Reduced Racial/Ethnic Disparities in Prescription Drug Use and Spending?
Article first published online: 17 SEP 2013
© Health Research and Educational Trust
Health Services Research
Volume 49, Issue 2, pages 502–525, April 2014
How to Cite
Mahmoudi, E. and Jensen, G. A. (2014), Has Medicare Part D Reduced Racial/Ethnic Disparities in Prescription Drug Use and Spending?. Health Services Research, 49: 502–525. doi: 10.1111/1475-6773.12099
- Issue published online: 27 MAR 2014
- Article first published online: 17 SEP 2013
- Manuscript Accepted: 24 JUN 2013
- Center for Retirement Research at Boston College. Grant Number: BC11-D4
- Blue Cross and Blue Shield of Michigan Foundation. Grant Number: 1699.SAP
- Medicare Part D;
- prescription drugs;
- utilization and spending;
- racial/ethnic disparities
To evaluate whether Medicare Part D has reduced racial/ethnic disparities in prescription drug utilization and spending.
Nationally representative data on white, African American, and Hispanic Medicare seniors from the 2002–2009 Medical Expenditure Panel Survey are analyzed. Five measures are examined: filling any prescriptions during the year, the number of prescriptions filled, total annual prescription spending, annual out-of-pocket prescription spending, and average copay level.
We apply the Institute of Medicine's definition of a racial/ethnic disparity and adopt a difference-in-difference-in-differences (DDD) estimator using a multivariate regression framework. The treatment group consists of Medicare seniors, the comparison group, adults without Medicare aged 55–63 years.
Difference-in-difference-in-differences estimates suggest that for African Americans Part D increased the disparity in annual spending on prescription drugs by $258 (p = .011), yet had no effect on other measures of prescription drug disparities. For Hispanics, DDD estimates suggest that the program reduced the disparities in annual number of prescriptions filled, annual total and out-of-pocket spending on prescription drugs by 2.9 (p = .077), $282 (p = .019) and $143 (p < .001), respectively.
Medicare Part D had mixed effects. Although it reduced Hispanic/white disparities related to prescription drugs among seniors, it increased the African American/white disparity in total annual spending on prescription drugs.