Differential returns on education by ethnicity and nativity in a cohort of older white and Asian Americans

Abstract

AbstractBackgroundAsian Americans generally have lower risk of dementia than white Americans. Education likely protects against dementia via direct development of cognitive reserve and indirectly via income and material resources. However, the protective effects of education may be weaker among Asian Americans due to lower income returns among the foreign‐born. We hypothesized that: (1) the effects of education may be weaker among Asians than whites; (2) the effects of education are weaker among foreign‐born than US‐born individuals.MethodWe followed a cohort of 5,974 Chinese, 4,601 Filipino, 3,071 Japanese, and 131,762 white Kaiser Permanente Northern California members for incident dementia (2002‐2020). We estimated hazard ratios (HRs) with age‐ and sex‐adjusted Cox proportional hazards models to examine whether estimated effects of college education (versus less than college degree) on dementia incidence differed by race/ethnicity (Asian versus white) and nativity (US‐ versus foreign‐born). Models were run for Asian ethnicities pooled and separately due to potential subgroup heterogeneity.ResultMean baseline age was 71.3 years (standard deviation, SD 7.7), and mean follow‐up time was 9.5 years (SD 4.6). The estimated effect of college education appeared slightly more protective against dementia incidence among Asian Americans than whites (HR 0.84 95% CI [0.76‐0.92] in Asian Americans, 0.89 [0.86‐0.91] in whites; Figure). There was heterogeneity across Asian groups. The estimated effect of college education (versus less than college) was most protective in Chinese individuals (0.73 [0.62‐0.85]) and Filipinos (0.80 [0.67‐0.95]), but null in Japanese (1.02 [0.84‐1.23]). College education also appeared more protective in foreign‐born vs. US‐born Asian Americans but not whites. Nativity results were also driven by strong effect modification among Chinese participants; other Asian ethnic group estimates were imprecise.ConclusionContrary to expectations, college education may confer slightly greater protection against dementia for Asian than white Americans, driven by differences among foreign‐born. Due to devaluing of education among immigrants, it is unlikely that social/material resources conferred by high education explain the greater protective effect in Asian Americans. However, there is substantial heterogeneity by Asian ethnicity, and additional work on the mechanisms driving differences by ethnicity and nativity (e.g. bilingualism, selective migration) is needed.