Background: Social determinants of health, such as primary insurance status, may unduly impact morbidity and mortality after joint surgery. We hypothesized that Medicaid versus private primary insurance status predicts in-hospital mortality after total knee arthroplasty (TKA).
Methods: We build regression models using generalized estimating equations with exchangeable correlation to test our hypothesis in patients in the State Inpatient Database from five states, who underwent primary TKA from January 2007 to December 2014.
Results: Medicaid patients had greater odds of in-hospital mortality compared to patients with private insurance (OR 1.73, 95% CI 1.01 - 2.95). Corroborating our primary analysis as potential mediators, Medicaid patients were also more likely to experience any postoperative complications (OR 1.25, 95% CI 1.18 - 1.33), pulmonary complications (OR 1.26, 95% CI 1.16 - 1.36), infection-related complications (OR 1.51, 95% CI 1.35 - 1.68), intraoperative complications (OR 1.25, 95% CI 1.03 - 1.52), longer length of stay (OR 1.09, 95% CI 1.08 - 1.10), and greater total charges (OR 1.03, 95% CI 1.02 - 1.04) relative to privately insured patients.
Conclusion: Medicaid insurance status is associated with higher in-hospital mortality and morbidity in patients after TKA compared to private insurance, even after controlling for potentially confounding patient characteristics and risk factors.
