Sex Differences in the Prevalence and Incidence of Cognitive Impairment: Does Immigration Matter?

Fengyan Tang, Iris Chi, Xin Qi Dong

Publication Date: 08/12/2019

OBJECTIVES: We aimed to examine the associations between immigration-related factors and prevalent and incident cognitive impairment (CI) and whether the associations varied by sex among US Chinese older adults.

DESIGN: Two-wave prospective study.

SETTING: The greater Chicago area.

PARTICIPANTS: Community-dwelling adults aged 60 and older who self-identified as Chinese, who were interviewed at two time points during 2011-2013 (N = 3157) and 2013-2015 (N = 2713).

MEASUREMENTS: CI was assessed by the 30-item Chinese Mini-Mental State Examination (C-MMSE). CI prevalence was determined by the percentage of respondents whose C-MMSE score was below 18 at baseline (N = 3033), and CI incidence was determined by the percentage of the respondents whose score was 18 or above at baseline (N = 2443) but dropped below 18 at wave 2. Immigration-related factors included age at migration, immigration reasons, and acculturation. RESULTS: The CI prevalence rate was 7.62% at baseline, and the incidence rate was 5.12% at wave 2. Women were more likely than men to have CI, consisting of 77.06% and 75.20% among persons with CI at the time points. None of the immigration-related factors were related to CI prevalence and incidence. Older age, fewer years of education, and more instrumental activities of daily living limitations were risk factors of CI in the whole, male, and female samples.

CONCLUSION: Older Chinese women were generally disadvantaged in cognition and overall health as compared with older Chinese men. Yet immigration experience does not link to CI for both men and women after equalizing the well-established effects of age and education on cognition. Future research needs to investigate whether the risk of CI in late life is related to the biological and contextual factors earlier in the life course. Decreasing sex disparities in the risk of dementia may focus on reducing educational and health disparities in the early life stage. J Am Geriatr Soc 67:S513–S518, 2019.