Disparities associated with Medicare Part D Star Ratings measures among patients with Alzheimer's disease and related dementias.

The Medicare Parts C and D Star Ratings system was established to improve care quality in Medicare. Previous studies reported racial/ethnic disparities in the calculation of medication adherence measures of Star Ratings in patients with diabetes, hypertension, and hyperlipidemia. This study aimed to identify possible racial/ethnic disparities in the calculation of adherence measures of Medicare Part D Star Ratings among patients with Alzheimer's disease and related dementias (ADRD) and diabetes, hypertension, or hyperlipidemia. This retrospective study analyzed the 2017 Medicare data and Area Health Resources Files. Non-Hispanic White (White) patients were compared to Black, Hispanic, Asian/Pacific Islander (Asian), and other patients on their likelihood of being included in the calculation of adherence measures for diabetes, hypertension, and/or hyperlipidemia. To adjust for the individual/community characteristics, logistic regression was used when the outcome is the inclusion in the calculation of one adherence measure; multinomial regression was used when examining the inclusion in the calculation of multiple adherence measures. Analyzing the data of 1438,076 Medicare beneficiaries with ADRD, this study found that Black (adjusted odds ratio, or OR = 0.79, 95% confidence interval, or 95% CI = 0.73-0.84) and Hispanic (OR = 0.82, 95% CI = 0.75-0.89) patients were less likely than White patients to be included in the calculation of adherence measure for diabetes medications. Further, Black patients were less likely to be included in the calculation of the adherence measure for hypertension medications than White patients (OR = 0.81, 95% CI = 0.78-0.84). All minorities were less likely to be included in calculating the adherence measure for hyperlipidemia medications than Whites. The ORs for Black, Hispanic, and Asian patients were 0.57 (95% CI = 0.55-0.58), 0.69 (95% CI = 0.64-0.74), and 0.83 (95% CI = 0.76-0.91), respectively. Minority patients were generally likely to be included in the measure calculation of fewer measures than White patients. Racial/ethnic disparities were observed in the calculation of Star Ratings measures among patients with ADRD and diabetes, hypertension, and/or hyperlipidemia. Future studies should explore possible causes of and solutions to these disparities.