Study Shows Geographic and Racial/Ethnic Variation in Glycemic Control and Treatment among Veterans with Diabetes
Diabetes affects more than 34 million Americans, but despite decades of effective treatments, control rates remain below recommended guidelines, with non-Hispanic blacks (NHB) and Hispanics having sub-optimal HbA1c control relative to non-Hispanic whites (NHW). Geography is a well-known determinant of health and an improved understanding of the relationships between geographic factors (social and environmental) and diabetes outcomes may lead to targeted interventions. This retrospective cohort study sought to answer the following questions: 1) Do rates of metabolic control exhibit geographic patterning or “hotspots”? and 2) Does patterning vary by race-ethnicity? Using an advanced spatial modeling framework, investigators analyzed data for a national cohort of more than 1.1 million Veterans who had received VA care for diabetes in one of 125 VAMC catchment areas in 2015. The primary outcome was sub-optimal glycemic control defined as HbA1c ≥ 8.0% for this study.
- After adjusting for age, gender, race-ethnic group, service-connected disability, marital status and comorbidities, the prevalence of uncontrolled diabetes varied by VA catchment area, with values ranging from 19% to 29%. These differences persisted after further adjustment for medication use and adherence, as well as use and access metrics.
- Disparities in sub-optimal control appeared consistent across most but not all catchment areas, with NHB and Hispanic Veterans having higher odds of sub-optimal control than NHW Veterans. Prevalence of uncontrolled diabetes in the VA catchment area with the poorest control rates was estimated as high as 28% for NHW, 30% for NHB, and 35% for Hispanics.
- Patterns of uncontrolled diabetes within VA did not mirror patterns of diabetes prevalence across the country. While high diabetes prevalence in the general population overlapped with sub-optimal diabetes control in parts of Appalachia, Georgia, Alabama, Mississippi, and Tennessee, parts of the Diabetes Belt had lower than average rates of uncontrolled diabetes in VA, indicating that areas of high diabetes prevalence can have below average rates of uncontrolled diabetes.
- Geographic as well as racial-ethnic differences in diabetes control rates were not explained by adjustment for demographics, comorbidity burden, use or type of diabetes medication, healthcare use, access metrics, or medication adherence, suggesting there is a geographic component to diabetes control that needs to be further explored. Potential geographic determinants include socioeconomic status as well as health care provider workforce differences between VAMCs and at the community level.
- There were limitations to the definition of VAMC catchment area, as there were counties with split utilization, e.g., 12% of patients routinely received care outside their assigned VA catchment area.
This study was funded by HSR&D. Drs. Hunt, Davis, Pearce, Bian, Axon, and Neelon are part of HSR&D’s Charleston Health Equity and Rural Outreach Innovation Center (HEROIC).
Hunt K, Davis M, Pearce J, Bian J, Guagliardo M, Moy E, Axon R, and Neelon B. Geographic and Racial/Ethnic Variation in Glycemic Control and Treatment in a National Sample of Veterans with Diabetes. Diabetes Care. October 2020;43(10):2460-2468.