Geographic and Racial/Ethnic Variation in Glycemic Control and Treatment in a National Sample of Veterans With Diabetes

Abstract

OBJECTIVE Geographic and racial/ethnic disparities related to diabetes control and treatment have not previously been examined at the national level. RESEARCH DESIGN AND METHODS A retrospective cohort study was conducted in a national cohort of 1,140,634 veterans with diabetes, defined as two or more diabetes ICD-9 codes (250.xx) across inpatient and outpatient records. Main exposures of interest included 125 Veterans Administration Medical Center (VAMC) catchment areas as well as racial/ethnic group. The main outcome measure was HbA1c level dichotomized at ≥8.0% (≥64 mmol/mol). RESULTS After adjustment for age, sex, racial/ethnic group, service-connected disability, marital status, and the van Walraven Elixhauser comorbidity score, the prevalence of uncontrolled diabetes varied by VAMC catchment area, with values ranging from 19.1% to 29.2%. Moreover, these differences largely persisted after further adjusting for medication use and adherence as well as utilization and access metrics. Racial/ethnic differences in diabetes control were also noted. In our final models, compared with non-Hispanic Whites, non-Hispanic Blacks (odds ratio 1.11 [95% credible interval 1.09–1.14]) and Hispanics (1.36 [1.09–1.14]) had a higher odds of uncontrolled HBA1c level. CONCLUSIONS In a national cohort of veterans with diabetes, we found geographic as well as racial/ethnic differences in diabetes control rates that were not explained by adjustment for demographics, comorbidity burden, use or type of diabetes medication, health care utilization, access metrics, or medication adherence. Moreover, disparities in suboptimal control appeared consistent across most, but not all, VAMC catchment areas, with non-Hispanic Black and Hispanic veterans having a higher odds of suboptimal diabetes control than non-Hispanic White veterans.