Effects of Medicare comprehensive medication review on racial/ethnic disparities in nonadherence to statin medications among patients with Alzheimer’s Disease: an observational analysis

Abstract Background Alzheimer’s Disease (AD) is the mostcommon cause of dementia, a neurological disorder characterized by memory loss and judgment impairment. Hyperlipidemia, a commonly co-occurring condition, should be treated to prevent associated complications. Medication adherence may be difficult for individuals with AD due to the complexity of AD management. Comprehensive Medication Reviews (CMRs), a required component of Medicare Part D Medication Therapy Management (MTM), have been shown to improve medication adherence. However, many MTM programs do not target AD. Additionally, racial/ethnic disparities in MTM eligibility have been revealed. Thus, this study examined the effects of CMR receipt on reducing racial/ethnic disparities in the likelihood of nonadherence to hyperlipidemia medications (statins) among the AD population. Methods This retrospective study used 2015-2017 Medicare data linked to the Area Health Resources Files. The likelihood of nonadherence to statin medications across racial/ethnic groups was compared between propensity-score-matched CMR recipients and non-recipients in a ratio of 1 to 3. A difference-in-differences method was utilized to determine racial/ethnic disparity patterns using a logistic regression by including interaction terms between dummy variables for CMR receipt and each racial/ethnic minority group (non-Hispanic Whites, or Whites, as reference). Results The study included 623,400 Medicare beneficiaries. Blacks and Hispanics had higher statin nonadherence than Whites: Compared to Whites, Blacks’ nonadherence rate was 4.53% higher among CMR recipients and 7.35% higher among non-recipients; Hispanics’ nonadherence rate was 2.69% higher among CMR recipients and 7.38% higher among non-recipients. Differences in racial/ethnic disparities between CMR recipients and non-recipients were significant for each minority group (p