Medicare Payments and ACOs for Dementia Patients Across Race and Social Vulnerability.

Objectives: This study investigated variations in Medicare payments for Alzheimer's disease and related dementia (ADRD) by race, ethnicity, and neighborhood social vulnerability, together with cost variations by beneficiaries' enrollment in Accountable Care Organizations (ACOs).

Methods: We used merged datasets of longitudinal Medicare Beneficiary Summary File (2016-2020), the Social Vulnerability Index (SVI), and the Medicare Shared Savings Program (MSSP) ACO to measure beneficiary-level ACO enrollment at the diagnosis year of ADRD. We analyzed Medicare payments for patients newly diagnosed with ADRD for the year preceding the diagnosis and for the subsequent 3 years. The dataset included 742,175 Medicare fee-for-service (FFS) beneficiaries aged 65 and older with a new diagnosis of ADRD in 2017 who remained in the Medicare FFS plan from 2016 to 2020.

Results: Among those newly diagnosed, Black and Hispanic patients encountered higher total costs compared to White patients, and ADRD patients living in the most vulnerable areas experienced the highest total costs compared to patients living in other regions. These cost differences persisted over 3 years postdiagnosis. Patients enrolled in ACOs incurred lower costs across all racial and ethnic groups and SVI areas. For ADRD patients living in the areas with the highest vulnerability, the cost differences by ACO enrollment of the total Medicare costs ranged from $4,403.1 to $6,922.7, and beneficiaries' savings ranged from $114.5 to $726.6 over three years post-ADRD diagnosis by patient's race and ethnicity.

Conclusions: Black and Hispanic ADRD patients and ADRD patients living in areas with higher social vulnerability would gain more from ACO enrollment compared to their counterparts.