Prevalence of Dementia in American Indians and Alaska Natives Compared to White, Black, and Hispanic Medicare Beneficiaries: Findings from the National Health and Aging Trends Study

Objective: To estimate the prevalence of dementia among American Indian and Alaska Native (AIAN) Medicare beneficiaries and compare the prevalence of dementia in AIANs and other racial and ethnic minority groups—non-Hispanic Blacks (NHBs) and Hispanics—with non-Hispanic Whites (NHWs) Medicare beneficiaries. Methods: We used survey data from Round 5 of the National Health and Aging Trends Study (NHATS, 2015) (N = 7,449), a nationally representative study of Medicare beneficiaries ages 65 years and older. We used logistic regression to estimate the age- and sex-adjusted prevalence of dementia with 95% confidence intervals by race/ethnicity as well as prevalence differences between groups. Results: The majority of participants were between 65 and 74 years old. Approximately half of them were female. NHWs had a prevalence of 5% for dementia, and AIAIs had a prevalence of 9%, four percentage points higher than NHWs (95%CI 1%, 11%). We estimated a similar difference in the prevalence of dementia in AIAN Medicare beneficiaries compared to NHBs. Conclusion: While previous research has reported that AIANs share a similar or lower prevalence of dementia than NHWs, our findings suggest a potentially higher prevalence of dementia among AIAN Medicare beneficiaries. A relatively small number of AIAN resulted in wide confidence intervals for many of our associations. Future research should focus on recruiting a larger sample and on dementia prevalence and unique risk factors within and among AIAN tribes.