Estimating prevalence of early Alzheimer's disease in the United States, accounting for racial and ethnic diversity

Introduction Updated estimates of the US Alzheimer's disease (AD) population, including under-represented populations, are needed to improve clinical trial diversity. Methods A step-wise approach calculating prevalent numbers from clinical syndrome to biomarker-positive mild cognitive impairment (MCI) due to AD and mild AD was developed, using age-and-race/ethnicity-stratified data where available. Results The estimated percentage of Americans aged >= 65 years with MCI due to AD was 9.2% of non-Hispanic Whites, 13.6% of non-Hispanic Blacks, 11.1% Hispanics, and 9.7% other race/ethnicities. The estimated percentage of Americans aged >= 65 years with mild dementia due to AD among non-Hispanic Whites was 3.7%, non-Hispanic Blacks 7.0%, Hispanics 5.3%, and 3.9% other race/ethnicities. Of these early-stage AD cases, few are likely diagnosed, ranging from 13% of prevalent non-Hispanic Black cases to 27% of non-Hispanic White cases. Discussion Under-representation in clinical trials may be improved by setting recruitment goals reflecting the diversity of the AD patient population and supporting efforts toward timely diagnosis.

Automated summary

Updated estimates of the US AD population, including under-represented populations, are needed to improve clinical trial diversity. The results indicate that a small proportion of early-stage AD cases are likely to be diagnosed, particularly among minority populations. Setting recruitment goals reflecting the diversity of the AD patient population and supporting efforts toward timely diagnosis may improve under-representation in clinical trials.