Exposure to School Racial Segregation and Late-Life Cognitive Outcomes.

Importance: Disparities in cognition, including dementia occurrence, persist between non-Hispanic Black (hereinafter, Black) and non-Hispanic White (hereinafter, White) older adults, and are possibly influenced by early educational differences stemming from structural racism. However, the association between school racial segregation and later-life cognition remains underexplored. Objective: To investigate the association between childhood contextual exposure to school racial segregation and cognitive outcomes in later life. Design, Setting, and Participants: This cross-sectional study examined a nationally representative sample of US older adults from the Health and Retirement Study. Both restricted childhood residence data and publicly available cognitive assessment data (survey years 1995-2018) were used for Black and White participants aged 65 years and older. Data analyses were performed from March 2, 2023, to October 22, 2024. Exposures: State-level Black and White dissimilarity index for public elementary schools in the late 1960s (range, 0-100) was used to measure school segregation. States were categorized into high segregation (≥83.6) and low segregation (<83.6) based on the top quintile. Main Outcomes and Measures: Cognitive scores, cognitive impairment, and dementia were assessed using the Telephone Interview for Cognitive Status and proxy assessment. Multilevel regression analyses were conducted stratified by race and ethnicity, adjusting for sociodemographic covariates. Potential early-life and midlife mediators, including educational attainment, were assessed. Results: The study sample included 3566 Black (16 104 observations) and 17 555 White (90 874 observations) participants. The mean (SD) age of the sample was 75.6 (7.5) years, and 62 187 (58.1%) were female. Participants exposed to high vs low segregation exhibited lower cognitive scores (13.6 vs 14.5) and a higher prevalence of cognitive impairment (37.0% vs 28.0%) and dementia (14.1% vs 9.3%). Multilevel analyses revealed a significant negative association between school segregation and later-life cognitive outcomes among Black participants, but not among White participants, after adjusting for covariates. Potential mediators across the life course, including educational attainment, explained 57.6% to 72.6% of the association, yet the findings were significant among Black participants for all outcomes. In the model including all mediators and covariates, Black participants exposed to high segregation exhibited significantly lower cognitive scores (coefficient, -0.26; 95% CI, -0.43 to -0.09) and a higher likelihood of cognitive impairment (adjusted odds ratio [AOR], 1.35; 95% CI, 1.12-1.63) and dementia (AOR, 1.26; 95% CI, 1.03-1.54). Conclusions and Relevance: This cross-sectional study of Black and White older individuals found that childhood exposure to school segregation was associated with late-life cognition among the Black population. Given the increasing amount of school segregation in the US, educational policies aimed at reducing segregation are needed to address health inequities. Clinicians may leverage patients' early-life educational circumstances to promote screening, prevention, and management of cognitive disorders.