The Affordable Care Act – Effects of Insurance on Diabetes Biomarkers
Research Design and Methods: Retrospective observational cohort study using electronic health record data from 178 community health centers (CHCs) in the ADVANCE network. We assessed changes in diabetes-related biomarkers among adult patients with diabetes in 10 Medicaid expansion states (n=25,279), comparing newly insured with continuously insured, discontinuously insured, and continuously uninsured patients pre- to post-ACA expansion. Primary outcomes included 24 months pre- to 24 months post-ACA changes in glycosylated hemoglobin (HbA1c), systolic (SBP) and diastolic (DBP) blood pressure, and low-density lipoprotein (LDL) cholesterol levels.
Results: Newly insured patients exhibited a reduction in adjusted mean HbA1c levels [8.24% (67 mmol/mol) to 8.17% (66 mmol/mol)], which was significantly different from continuously uninsured patients, whose HbA1c levels increased [8.12% (65 mmol/mol) to 8.29% (67 mmol/mol); difference-in-difference (DID)=-0.24%; p<0.001]. Newly insured patients showed greater reductions in adjusted mean SBP than continuously uninsured patients (DID=-1.8 mmHg; p<0.001), DBP (DID=-1.0 mmHg; p<0.001), and LDL (DID=-3.3 mg/dL; p<0.001). Among patients with elevated HbA1c in the 3 months prior to expansion, newly insured patients were more likely than continuously uninsured to have a controlled HbA1c measurement by 24 months post-ACA [Hazard Ratio=1.25; 95% CI=1.02-1.54].
Conclusions: Post-ACA, newly insured patients had greater improvements in diabetes-related biomarkers than continuously uninsured, discontinuously insured, or continuously insured patients. Findings suggest that health insurance gain via ACA facilitates access to appropriate diabetes care, leading to improvements in diabetes-related biomarkers.