Alzheimer's disease and related dementias (ADRD) after COVID‐19 infection: trends and disparities

INTRODUCTION Coronavirus disease 2019 (COVID‐19) may accelerate neurocognitive decline, but its association with incident mild cognitive impairment (MCI), Alzheimer's disease and related dementias (ADRD), and racial and ethnic disparities remains unclear. METHODS We analyzed 2019 to 2022 nationwide Medicare Advantage claims (Optum's Clinformatics Data Mart) to assess new MCI/ADRD diagnoses after COVID‐19 among adults ≥ 65 without prior cognitive disease ( N = 2,492,122; mean age 75.5; 56% female; 3.6% Asian, 10.9% Black, 11.5% Hispanic, 73.9% White; 12.1% infected). Propensity score‐matched, multivariable, and instrumental variable competing‐risk models were adjusted for demographics, comorbidities, contextual factors, and competing mortality. RESULTS Overall, 15.5% developed MCI/ADRD. COVID‐19 was associated with ≈ 1.4 × higher subhazard and a 4 percentage‐point increase in 32‐month incidence. Relative risks were similar across groups, but higher infection rates among Black and Hispanic beneficiaries widened disparities. DISCUSSION COVID‐19 increases new MCI/ADRD risk. Disparities appear driven by unequal infection exposure and health conditions, highlighting the need for targeted prevention and cognitive care.