1992-LB: Area Deprivation Index of Participants in the Rare and Atypical Diabetes Network (RADIANT)

Introduction & Objective: RADIANT is a multicenter, US-based study of the causes of atypical diabetes and how it informs overall understanding of diabetes etiology and heterogeneity. A key goal is equitable inclusion so that knowledge gained will be broadly applicable. Populations at risk for underrepresentation in research include those with low socioeconomic status. We assessed area deprivation index (ADI), a census-based socioeconomic index, of RADIANT participants. We evaluated the relationship of ADI with participant characteristics.

Methods: Participants with valid U.S. addresses and available ADI ranking were included in the study. Participant characteristics were summarized; 2021 ADI values were constructed based on participant address. ADI values were compared to the expected value of 50^th percentile via the Wilcoxon test and compared among groups via the Kruskal-Wallis test.

Results: There were 892 RADIANT participants included in the analysis. The median U.S. ADI of participants was 28, lower than the expected value of 50 (p<0.001). Only 24.5% of participants had ADI >50^th percentile. Median ADI differed by race, but not ethnicity, with Asian participants having the lowest median ADI (13), compared to Blacks (29) and Whites (29) (p<0.01). Median ADI did not differ by referral source (e.g., provider vs. self-referral). ADI compared across ~3 consecutive years was statistically different (Median ADI 24, 30, 29; p<0.05), driven by an increase from year 1 to year 2.

Conclusion: This study found that a low number of RADIANT participants live in areas of high deprivation, suggesting ascertainment bias in enrollment and highlighting the need for continued development of recruitment practices that will engage individuals likely to face barriers to research participation and who simultaneously carry a higher disease burden from diabetes.