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In the US, dementia risk is higher in non-Hispanic Black individuals than in non-Hispanic White individuals. To evaluate progress toward reducing such disparities, tracking secular trends in racial disparities in dementia prevalence is essential. OBJECTIVE To examine whether relative racial disparities in dementia prevalence or incidence have changed in the US from 2000 to 2016. DESIGN, SETTINGS, AND PARTICIPANTSThe Health and Retirement Study (HRS) is a nationally representative study of adults 50 years or older. New participants are recruited every 6 years, and study visits occur biennially. Approximately 17 000 to 22 000 respondents have been surveyed at each wave since 2000, achieving response rates of 81% to 89%. Data for this cohort study were obtained from non-Hispanic White and non-Hispanic Black participants aged 70 years and older from the 2000 to 2016 waves. For analyses of secular trends in racial disparities in dementia prevalence, each HRS wave was considered separately (range of participants meeting eligibility criteria in each wave, 6322-7579). For analyses of secular trends in racial disparities in dementia incidence, 7 subcohorts were created (range of participants meeting eligibility criteria in each subcohort, 5322-5961) following up people without dementia for 4 years from subcohort baseline visits

Introduction Systematic disparities in misdiagnosis of dementia across racial/ethnic groups have implications for health disparities. We compared the risk of dementia under‐ and overdiagnosis in clinical settings across racial/ethnic groups from 2000 to 2010. Methods We linked fee‐for‐service Medicare claims to participants aged ≥70 from the nationally representative Health and Retirement Study. We classified dementia status using an algorithm with similar sensitivity and specificity across racial/ethnic groups and assigned clinical dementia diagnosis status using ICD‐9‐CM codes from Medicare claims. Multinomial logit models were used to estimate relative risks of clinical under‐ and overdiagnosis between groups and over time. Results Non‐Hispanic blacks had roughly double the risk of underdiagnosis as non‐Hispanic whites. While primary analyses suggested a shrinking disparity over time, this was not robust to sensitivity analyses or adjustment for covariates. Risk of overdiagnosis increased over time in both groups. Discussion Our results suggest that efforts to reduce racial disparities in underdiagnosis are warranted.