Early-Life Circumstances and Racial Disparities in Cognition Among Older Adults in the US

Abstract

ImportanceGiven the critical role of neurocognitive development in early life, understanding the association between early-life circumstances and racial disparities in cognition has important implications.ObjectiveTo assess whether racial differences in early-life circumstances are collectively and individually associated with racial disparities in late-life cognition among older adults in the US.Design, Setting, and ParticipantsThis cross-sectional study used comprehensive life history data from the Health and Retirement Study, a nationally representative survey of US adults 50 years or older. Data analyses were performed from August 9, 2022, to January 20, 2024.Main Outcomes and MeasuresRacial differences in early-life circumstances and racial disparities in late-life cognition were investigated using a Blinder-Oaxaca decomposition regression model. Cognitive outcomes, including cognitive score and cognitive impairment, were evaluated using the Telephone Interview for Cognitive Status. Early-life educational experiences were primary explanatory variables; early-life cohort, regional, financial, health, trauma, family relationship factors, and educational attainment were additional explanatory variables; demographic and genetic factors were covariates.ResultsThe study sample comprised 9015 participants; 1634 non-Hispanic Black (hereafter, Black) individuals (18.1%) and 7381 non-Hispanic White (hereafter, White) individuals (81.9%). Among Black participants, the mean (SD) age was 69.2 (9.2) years and 1094 (67.0%) were women. Among White participants, the mean (SD) age was 73.2 (10.1) years and 4410 (59.7%) were women. Cognitive scores (scale, 0-27) were significantly lower among Black participants (13.5 [95% CI, 13.3-13.7] points) than among White participants (15.8 [95% CI, 15.7-15.9] points), while the prevalence of cognitive impairment (cognitive score <12) was significantly higher among Black participants (33.6 [95% CI, 31.3-35.9] percentage points [ppt]) than among White participants (16.4 [95% CI, 15.6-17.2] ppt). Substantial racial differences were observed in early-life circumstances. Overall, differences in early-life circumstances were associated with 61.5% of the racial disparities in cognitive score (1.4 [95% CI, 0.88-2.0] points), and 82.3% of the racial disparities in cognitive impairment (14.2 [95% CI, 8.8-19.5] ppt), respectively. In multivariable analyses, early-life educational experiences were associated with 35.2% of the disparities in cognitive score and 48.6% in cognitive impairment. Notably, school racial segregation (all segregated schooling before college) was associated with 28.8% to 39.7% of the racial disparities in cognition. These findings were consistent in a series of sensitivity analyses.Conclusions and RelevanceThe findings of this cross-sectional study suggest that less favorable early-life circumstances are associated with clinically meaningful racial disparities in late-life cognition. Policies that improve educational equity have the potential to reduce racial disparities in cognition in older ages. Clinicians may leverage early-life circumstances to promote the screening, prevention, and interventions of cognitive impairment more efficiently, thereby promoting health equity.

Association of Childhood Exposure to School Racial Segregation with Late-Life Cognitive Outcomes among Older Americans

“…Our study underscores that the negative association between school segregation and cognitive outcomes is more pronounced for Black than White participants, consistent with previous reseearch. 9,21,25,46 Moreover, our findings suggest that SES may explain a significant portion of the association between school segregation and cognition. We observed an approximately 50% reduction in the association among Black individuals after accounting for SES, highlighting the role of SES as potential mediators linking school segregation and cognition.…”

“…Our results align with existing literature highlighting the negative association between adverse earlylife educational experiences and cognition in later life. 9 Notably, an increasing number of studies have indicated that higher educational quality is linked to a reduced risk of dementia and improved cognitive outcomes in later life. 41 , 42 Our analysis, drawing from comprehensive national datasets, offers broader contextual insights into the relationship between school segregation and cognition, setting it apart from studies that have relied on self-reported 19 – 21 or regional-specific data, 19 , 22 and/or those that have not focused specifically on cognition.…”

“…Our study underscores that the negative association between school segregation and cognitive outcomes is more pronounced for Black than White participants, consistent with previous reseearch. 9 , 21 , 25 , 46 …”

“… 4 , 5 , 6 Racial differences in early educational environments, particularly those rooted in structural racism, appear pivotal in shaping cognition in later life. 7 – 9 …”

“…4,5,6 Racial differences in early educational environments, particularly those rooted in structural racism, appear pivotal in shaping cognition in later life. [7][8][9] School racial segregation (school segregation hereafter), a significant aspect of United States (US) education systems, may exert a particularly profound impact on cognition. 10 This practice physically segregates students in educational institutions based on racial backgrounds, resulting in vastly unequal educational experiences, qualities, and opportunities between White and minoritized populations.…”