Diabetes Control During Massachusetts Insurance Reform.

Racial/ethnic disparities in glycemic control-a key diabetes outcome measure-continue to widen, even though the overall prevalence of glycemic control in the US has improved. Health insurance coverage may be associated with improved glycemic control, but few studies examine effects during a period of policy change. We assessed changes in glycemic control by racial/ethnic groups following the Massachusetts Health Insurance Reform for patients at two urban safety-net academic health systems between January 2005 and December 2013. We analyzed outcomes for three measures of poor glycemic control: 1) lack of a hemoglobin A1C (A1C) measure during a 6-month period; 2) A1C >8%; 3) A1C >9% before, during, and after implementation of insurance reform. We did not find increased rates of A1C monitoring or control following insurance reform overall or for specific racial/ethnic groups. We found evidence of worsened, not improved, glycemic control in some racial/ethnic groups in the post-reform period. The expansion of affordable insurance coverage was not associated with improved glycemic control in vulnerable populations.