Associations Between ACO Enrollment Status and Drug and Nondrug Costs Among Older Adults Newly Diagnosed With ADRD.

OBJECTIVE: Despite the promising role of accountable care organizations (ACOs) in improving care coordination and lowering total costs of care, it is unclear whether ACO enrollment leads to reduced drug costs among individuals with Alzheimer's disease and related dementias (ADRD). This longitudinal cohort study examined the long-term effects of ACO enrollment on drug and nondrug Medicare payments among Medicare beneficiaries with ADRD, focusing on their comorbidity burden. SETTING, PARTICIPANTS, AND MEASUREMENTS: This study tracked annual Part D prescription drug and nondrug payments of 111,235 fee-for-service Medicare beneficiaries newly diagnosed with ADRD one year prior and five years after the ADRD diagnosis year (2017) by their ACO enrollment and comorbidity burden status. Comorbidity burden was assessed based on the number of comorbidities ADRD patients had, categorized into no multiple chronic conditions (No MCC; 0 or 1), low MCC (2-4), and multisystem morbidity (MM; 5≤) groups. RESULTS: ACO enrollees spent significantly less on both drug and nondrug payments than non-ACO enrollees, with greater payment differences observed among those with higher comorbidity burden. Drug payment differences ranged from $55 to $93 among those with low MCC and $70-$119 among those with MM. Nondrug payment differences were the greatest during the diagnosis year, with $1,666 for those with MCC and $3,670 for those with MM. CONCLUSIONS: The findings of this study underscore meaningful differences in prescription drug and nondrug payments associated with ACO enrollment among Medicare beneficiaries with ADRD, particularly among those with greater coexisting comorbidity burden.