Referral Sources Across Racial and Ethnic Groups at Alzheimer's Disease Research Centers.

Background: Despite the need to increase engagement of underrepresented groups (URG) in Alzheimer's disease and related dementias (ADRD) studies, enrollment remains low. Objective: Compare referral sources across racial and ethnic groups among participants enrolled in ADRC studies. Methods: Data for this cross-sectional secondary analysis were extracted from the National Alzheimer's Coordinating Center Uniform Data Set. We performed mixed effects logistic regression models using generalized estimating equations for professional referral versus non-professional referral by racial and ethnic group, adjusted for age, gender, education, visit year, and Clinical Dementia Rating scale (CDR) with a random effect for study site. Results: Included in the analysis were 48,330 participants across 46 ADRCs (mean [SD] age, 71.3 [10.5] years; 20,767 female [57%]; 4,138 Hispanic [8.6%]; 1,392 non-Hispanic Asian [2.9%]; 6,766 non-Hispanic Black [14%] individuals; and 676 individuals [1.4%] of other races. Non-Hispanic Black and Asian participants had lower odds of being referred by a professional contact compared to non-Hispanic White participants (Black: adjusted OR = 0.61, 95% CI = 0.44-0.86, p = 0.005; Asian: adjusted OR = 0.65, 95% CI, p = 0.004). In participants who had completed an MRI, there was no significant difference in referral source across ethnic and racial groups. Conclusions: Further studies are needed to better understand the systemic and structural factors that contribute to differences in referral sources and disparities in recruitment of URG into ADRD studies.