Diabetic Retinopathy Outcomes Among Unhoused Individuals: A Big Data Analysis

PURPOSE: To evaluate diabetic retinopathy (DR) severity, vision-threatening complications (VTCs), treatment patterns, and longitudinal outcomes among unhoused individuals with diabetes compared with stably housed controls. METHODS: Using a large multicenter electronic health records network, patients with type 1 or type 2 diabetes were stratified by unhoused status via ICD-10 coding. Baseline DR severity, VTCs, and initial treatments were assessed across 9,643 unhoused and 1,180,509 housed patients. A secondary analysis requiring ≥6 months of ophthalmic follow-up yielded propensity score-matched cohorts of 2,911 patients each, with incident complications and treatments evaluated at one year. Multivariate Cox regression assessed the independent association between unhoused status and proliferative diabetic retinopathy (PDR) risk relative to other social determinants of health. RESULTS: At presentation, unhoused patients had significantly higher rates of PDR (5.24% vs 1.46%), vitreous hemorrhage (VH, 4.04% vs 1.03%), and tractional retinal detachment (TRD, 1.34% vs 0.24%) (all P<.01), and were less likely to achieve at least 6 months of follow-up (30.3% vs 55.2%; P<.01). In matched analysis, unhoused status increased 1-year risks of VH (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.08-1.69), diabetic macular edema (DME, HR, 1.28; 95% CI, 1.17-1.40), and PDR (HR, 1.25; 95% CI, 1.08-1.44). In multivariate analysis incorporating social determinants, unhoused status independently increased PDR risk (HR, 1.55; 95% CI, 1.41-1.71; P<.0001). CONCLUSIONS: Unhoused individuals present with more advanced DR, higher VTC rates, altered treatment patterns, and markedly reduced follow-up. These findings highlight unhoused status as a critical determinant of DR outcomes and underscore the need for targeted screening and socially informed ophthalmic care.