The influence of health insurance stability on racial/ethnic differences in diabetes control and management

Objective: This study examined whether health insurance stability was associated with improved type 2 diabetes mellitus (DM) control and reduced racial/ethnic health disparities. Methods: We utilized electronic medical record data (2005-2013) from two large, urban academic health systems with a racially/ethnically diverse patient population to examine insurance coverage, and three DM outcomes (poor diabetes control, A1 >= 8.0%; very poor diabetes control A1c >9.0%; and poor BP control, >= 130/80 mm Hg) and one DM management outcome (A1c monitoring). We used generalized estimating equations adjusting for age, sex, comorbidities, site of care, education, and income. Additional analysis examined if insurance stability (stable public or private insurance over the six-month internal) moderates the impact of race/ethnicity on DM outcomes. Results: Nearly 50% of non-Hispanic (NH) Whites had private insurance coverage, compared with 33.5% of NH Blacks, 31.5% of Asians, and 31.1% of Hispanics. Overall, and within most racial/ethnic groups, insurance stability was associated with better glycemic control compared with those with insurance switches or always being uninsured, with uninsured NH Blacks having significantly worse BP control. More NH Black and Hispanic patients had poorly controlled (A1c.8%) and very poorly controlled (A1c>9%) diabetes across all insurance stability types than NH Whites or Asians. The interaction between insurance instability and race/ethnic groups was statistically significant for A1c monitoring and BP control, but not for glycemic control. Conclusion: Stable insurance coverage was associated with improved DM outcomes for all racial / ethnic groups, but did not eliminate racial ethnic disparities.