Dementia Prevalence in Older Adults: Variation By Race/Ethnicity and Immigrant Status

Background and Purpose

A recent review of research on racial and ethnic differences in prevalence of dementia reported that in the U.S. non-Hispanic Blacks (NHB) have roughly double the prevalence of dementia, and Hispanics about 50% higher prevalence of dementia, in comparison to non-Hispanic Whites (NHW).  A recent article focused on U.S. and Mexican-born Hispanics, and NHB and NHW born in the U.S. showed that consideration of immigrant status has important effects on rates of cognitive impairment. Few studies have examined whether immigrant status moderates the relationship between race/ethnicity and dementia prevalence except in Hispanics. This is important to understand given projections that the number of older adult immigrants over age 65 in the U.S. will increase from 2.7 million in 1990 to more than 16 million by 2050. Using population-based data, we addressed the following questions: 1) Does prevalence of probable dementia vary by immigrant status?; 2) Are the associations between race/ethnicity and probable dementia moderated by immigrant status?; and 3) Are there differences in risk factors for probable dementia by race/ethnicity?

Methods

The current study used the first round (2011) of the National Health and Aging Trends Study (NHATS, N= 5,411). We used binary logistic regression to analyze risk factors (i.e., race, immigrant status, age, gender, marital status, education, numbers of people in household, and numbers of health conditions) associated with probable dementia among NHW, NHB, and Hispanic Medicare beneficiaries.

Results

Immigrant status moderated the associations between race/ethnicity and probable dementia. Hispanic and NHB immigrants had higher prevalence of dementia compared to their U.S. born counterparts; whereas NHW U.S. born individuals had a higher prevalence of dementia compared to NHW immigrants. Risk factors for dementia varied considerably between the three racial/ethnic groups.

Conclusion and Implications

While previous research has consistently reported that in the U.S. NHBs and Hispanics have higher prevalence of dementia than NHW, this relationship is more complex when immigrant status is also considered. Immigrant status may have complex effects on dementia risk due to factors such as selection factors affecting immigration, varied health and educational systems in diverse countries of origin, acculturative stress, and varied access to services in the U.S. With projections that there will be increased racial/ethnic diversity, and 16 million immigrant older adults in the U.S. by 2050, further research focused on understanding differences in dementia prevalence and risk by race/ethnicity and immigrant status are critical. Preparation for culturally competent health care systems to provide care for increasingly diverse people with dementia and their families will remain an important challenge.