Resumen de Racial and Ethnic Differences in Initiation and Discontinuation of Antidementia Drugs by Medicare Beneficiaries
Carolyn T. Thorpe, Nicole R. Fowler, Katherine Harrigan, Xinhua Zhao, Yihuang Kang, Joseph T. Hanlon, Walid F. Gellad, Loren J. Schleiden, Joshua Thorpe
Objectives To examine racial and ethnic differences in initiation and time to discontinuation of antidementia medication in Medicare beneficiaries.
Design Retrospective cohort study.
Setting Secondary analysis of 2009–10 enrollment, claims, and Part D prescription data for a 10% national sample of U.S. Medicare fee-for-service beneficiaries.
Participants Beneficiaries aged 65 and older with Alzheimer's disease or related dementia (ADRD) before 2009 and no fills for antidementia medications in the first half of 2009 (N = 84,043).
Measurements Initiation was defined as having one or more fills for antidementia medication in the second half of 2009 and discontinuation as a gap in coverage of 30 days or more during the year after initiation. The Andersen Behavioral Model was used to guide covariate selection.
Results Overall, 3,481 (4.1%) of previous nonusers initiated antidementia medication in the second half of 2009. Of those initiating one drug class (acetylcholinesterase inhibitors (AChEIs) or memantine), 9% later added the other class, and 2% switched classes. Of initiators, 23% discontinued within 1 month, and 62% discontinued within 1 year. Hispanic beneficiaries were more likely than white beneficiaries to initiate (adjusted odds ratio = 1.25, 95% confidence interval (CI) = 1.10–1.41). Black and white beneficiaries did not differ in likelihood of initiation. Hispanic (adjusted hazard ratio (aHR) = 1.56, 95% CI = 1.34–1.82) and black (aHR = 1.25, 95% CI = 1.08–1.44) beneficiaries discontinued at a faster rate than white beneficiaries.
Conclusion Initiation of antidementia medications was no different in black and white beneficiaries and more likely in Hispanic beneficiaries; black and Hispanic beneficiaries discontinued at a faster rate. More research into reasons explaining these differences is needed.
