Neighborhood disadvantage and the incidence of dementia in US Black women

INTRODUCTION: We investigated the association of neighborhood disadvantage with the incidence of Alzheimer's disease and related dementias (ADRD) in the longitudinal Black Women's Health Study (BWHS). METHODS: The study included 10,915 BWHS participants enrolled in Medicare for at least 1 year from 2012 to 2020. The Area Deprivation Index (ADI) was assigned to participant residential block groups over follow-up. ADRD cases were identified from Medicare files. RESULTS: Age- and education-adjusted hazard ratios (HRs) for ADRD increased as neighborhood disadvantage increased, to 1.42 (95% confidence interval [CI] 1.06–1.91) in the most disadvantaged quintile compared to the least disadvantaged quintile, with a significant linear trend (p = 0.012). Associations remained, although somewhat attenuated, when individual income was controlled. DISCUSSION: The present study adds to the evidence showing an association between living in a disadvantaged neighborhood and poorer brain health. The area-level association of deprivation with ADRD was in part explained by individual differences in socioeconomic status (SES). Highlights: The study assessed neighborhood deprivation in the largest cohort of US Black women. Cases of dementia were ascertained from Medicare claims files over 9 years of follow-up. Higher levels of area deprivation were associated with higher dementia risk.