Aging
Sex Differences in Dementia Prevenance in China and Taiwan: A Comparative Decomposition Analysis Yan-Jhu Su* Yan-Jhu Su Su The Pennsylvania State University
Background: Women have higher dementia risk than men across countries, yet the biopsychosocial factors underlying this sex gap remain unclear.
Methods: We analyzed nationally representative samples of adults aged ≥60 years from the 2018 China Health and Retirement Longitudinal Study (n=8,364) and the 2019 Taiwan Longitudinal Study of Aging (n=4,753). Population-level dementia prevalence was defined as the proportion of participants scoring ≤12 on Mini-Mental State Examination in China or ≤10 on the Montreal Cognitive Assessment in Taiwan. We considered biopsychological risk factors including education, cardiovascular problems, and health behaviors. Blinder–Oaxaca decomposition method was used to partition the male–female gap into differences due to endowment (population composition) and coefficient (association with dementia).
Results: In China, dementia prevalence was 3.9% among men and 13.9% among women (10.0 percentage-point [pp] difference, 95% CI: 11.4 to 8.6 pp). This sex difference was largely explained by endowments, particularly lower educational (6.2 pp) and higher IADL limitations (0.5 pp) among women, whereas coefficient changes played a small counterproductive role (4.5 pp). In Taiwan, dementia prevalence was 4.0% in men and 12.7% in women (8.7 pp difference, 95% CI: 10.2 to 7.1 pp). Similarly, most of the sex gap was attributable to endowments (8.0 pp), including lower education (5.0 pp), higher nonmarriage (0.8 pp), and more IADL limitations (0.8 pp), while coefficient effects were modest and nonsignificant.
Conclusions: Women in both China and Taiwan exhibit substantially higher dementia prevalence when using literature-based thresholds. In both datasets, sex differences are driven primarily by lower education and functional disadvantage rather than differential cardiovascular vulnerability or health behaviors, highlighting education and functional health as intervention opportunities for reducing sex difference in dementia prevalence cross populations.
