1406-P: Accessibility of Diabetes Prevention Programs in Historically Redlined Areas of the U.S.

Introduction & Objective: Prior research demonstrated an association between historical redlining practices and diabetes-related mortality. The National DPP is an evidence-based, cost-effective, structured lifestyle change intervention to prevent type 2 diabetes (T2D). Whether historical redlining practices drive the present-day availability of DPP programs across the US is unknown.

Methods: In person and hybrid DPPs across the US and their addresses were identified from the CDC. Walking distance accessibility was defined as a 0.8 km radius. Redlining was assessed using the 1930s federal Home Owners’ Loan Corporation (HOLC) maps by intersect spatial join onto 2020 census tracts. HOLC areas are classified into 4 grades: A (best), B (still desirable), C (declining), and D (hazardous). We examined the association between grade D vs. A-C tracts and the number of DPPs using a negative binomial mixed-effects model with random intercepts by geographic level and controlling for tract-level population, proportion uninsured people, and <150% of federal poverty line (FPL).

Results: Of 1730 DPPs, 347 were within walking access of a HOLC-graded tract centroid in 38 states. Nationally, after controlling for tract-level characteristics, grade D tracts and tracts with greater proportion <150% of FPL were associated with greater number of DPPs, while tracts with greater proportion of uninsured were associated with fewer DPPs within walking distance. In state-specific analyses for 7 of 33 examined states, there was statistically significant greater than expected DPP availability in grade D tracts. There was no difference in 20 states, while remaining 11 states could not be examined due to lack of HOLC data, model diagnostics, data sparsity, or convergence failure.

Conclusion: While availability of walking distance DPPs is higher in historically redlined areas in 7 states, there was no such enrichment in 20 states. Future research needs to examine DPP utilization by residents in these communities.