The Disparities of Coronary Artery Bypass Grafting Surgery Outcomes by Insurance Status: A Retrospective Cohort Study, 2007-2014.

BACKGROUND: Coronary artery bypass grafting (CABG) surgery is the gold standard treatment for complex coronary artery disease. Social determinants of health, including primary payer status, are disproportionately associated with adverse outcomes following surgical operations. We sought to examine associations between insurance status, in particular having Medicaid public insurance, and postoperative outcomes following isolated CABG surgeries.

METHODS: A retrospective review was performed using Florida, California, New York, Maryland, and Kentucky State Inpatient Databases (2007-2014) for isolated CABG patients ≥ 18 years. Multivariate regression for postsurgical inpatient mortality, postsurgical complications, 30- and 90-day readmission rates, total charges, and length of stay yielded adjusted odds ratios (ORs) reported for outcomes by insurance status.

RESULTS: Among 312,018 individuals, patients with Medicaid insurance and those designated as Uninsured incurred increased adjusted ORs of postsurgical inpatient mortality (56 and 64%, respectively) compared to Private Insurance. Additionally, Medicaid had the highest adjusted OR for 30-day readmission (OR 1.52, 95% CI 1.45-1.59), 90-day readmission (OR 1.53, 95% CI 1.47-1.59), postsurgical complications (OR 1.10, 95% CI 1.07-1.14) including pulmonary and infectious complications, postoperative length of stay, and total hospital charges (2016 dollars).

CONCLUSIONS: Medicaid insurance, compared to Private Insurance, is significantly associated with worse outcomes after isolated CABG. Our results demonstrate that Medicaid as a patient's primary insurance payer is an independent predictor of perioperative risks. Further research may help explain the reasons for the differences in payer groups.