Exclusions affect representativeness of Alzheimer's disease trial participants.

BACKGROUND: This study assessed how medical exclusion criteria of a prevention Alzheimer's disease trial impact potential eligibility and sample characteristics. METHODS: Medical exclusion criteria from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial were applied to N = 3695 participants from the population-based Health Retirement Study (HRS) with linked Medicare data. We determined the proportion of hypothetical eligibility. Multivariate Poisson regression was used to estimate associations between sociodemographic characteristics and eligibility. RESULTS: Of the participants, 74.2% (N = 2742) were deemed ineligible. Accounting for all sociodemographic characteristics, older age, female gender, fewer years of education, lower net worth, and body mass index of 30+ was associated with a higher odds of being deemed ineligible. Ethnocultural identity and living arrangement were not associated with eligibility. CONCLUSIONS: Our results suggest that certain sociodemographic factors may limit eligibility for a prevention Alzheimer's disease trial due to the presence of exclusionary medical conditions. This highlights the need to make trials more inclusive. HIGHLIGHTS: A total of 2742 participants (74.2%) were deemed ineligible for the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial based on the medical exclusion criteria.The most common medical exclusion in this sample was for cardiovascular conditions.Ineligibility was associated with age, education, net worth, and body mass index.