Objective: As the U.S. population ages, there have been projections that the number of people living with diabetes would double in the next two decades. Our objective is to track how diabetes prevalence rates have changed over time before and after the Affordable Care Act (ACA) among Medicare beneficiaries residing in the Diabetes Belt compared to those residing outside.

Methods: We used complete Medicare Beneficiary Summary Files for 2006 - 2015 (A/B/C/D and Chronic Conditions segments) to compute prevalence rates of diabetes as identified in the CMS Chronic Conditions Warehouse. The Diabetes Belt in this study was defined as 644 counties across southeastern counties in the U.S. that had diabetes prevalence ≥ 11% in 2008 (Barker et al. 2012).

Results: Overall diabetes prevalence increased from 24.4% in 2006 to 27.2% in 2011 and slightly decreased to 26.7% in 2015. In the Diabetes Belt, the prevalence rates were 29.1% in 2006, reaching 32.0% in 2012. The prevalence rates were 5.2% higher in absolute percentages in the Belt than outside in 2006. This difference steadily increased to 5.6% in 2015. After adjusting for age, sex, race, rurality, health professional shortage area designation, and economic level in counties, individuals in the Diabetes Belt experienced 8.1% higher risk (OR = 1.081; 95% CI = 1.078, 1.083) of having diabetes compared to those outside the Belt in 2015.

Discussion: Diabetes prevalence was stable among Medicare beneficiaries in 2011-2015, but the gap between the Diabetes Belt and the non-Belt counties widened throughout the study period. The ACA and the concerted efforts at diabetes prevention have succeeded in “bending the curve” on the projected increased in the number of persons with diabetes, but growing disparities in diabetes prevalence between the Diabetes Belt and other regions is a concern that requires more policy attention.


M. Sohn: None. S. Kim: None. H. Kang: None. T.L. McMurry: None. J.M. Lobo: None.


National Institutes of Health (R01DK113295)

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