Disparities in Acute and Chronic Complications of Diabetes Along the U.S. Rural-Urban Continuum

Objective: To determine the relative hazards of acute and chronic diabetes complications among those with diabetes across the U.S. rural-urban continuum.

Research Design and Methods: This retrospective cohort study used OptumLabs® Data Warehouse, a deidentified dataset of U.S. commercial and Medicare Advantage beneficiaries to follow 2,901,563 adults (age>18) with diabetes between January 1, 2012 and December 31, 2021. We compared adjusted hazard ratios of diabetes complications in remote areas (population <2,500), small towns (population 2,500-50,000), and cities (population >50,000).

Results: Compared to residents of cities, residents of remote areas had greater hazards of myocardial infarction (HR 1.06, 95% CI 1.02-1.10) and revascularization (HR 1.04, 1.02-1.06) but lower hazards of hyperglycemia (HR 0.90, 0.83-0.98) and stroke (HR 0.91, 0.88-0.95). Compared to cities, residents of small towns had greater hazards of hyperglycemia (HR 1.06, 1.02-1.10), hypoglycemia (HR 1.15, 1.12-1.18), end-stage kidney disease (HR 1.04, 1.03-1.06), myocardial infarction (HR 1.10, 1.08-1.12), heart failure (HR 1.05, 1.03-1.06), amputation (HR 1.05, 1.02-1.09), other lower extremity complications (HR 1.02, 1.01-1.03), and revascularization (HR 1.05, 95% CI 1.04-1.06) but smaller hazard of stroke (HR 0.95, 0.94-0.97). Compared to small towns, those in remote areas had lower hazard of hyperglycemia (HR 0.85, 0.78-0.93), hypoglycemia (HR 0.92, 0.87-0.97), and heart failure (HR 0.94, 0.91-0.97). Hazards of retinopathy and atrial fibrillation/flutter did not vary geographically.

Conclusions: Adults in small towns were disproportionately impacted by complications of diabetes. Future studies should probe for the reasons underlying these disparities.