Does payer status impact clinical outcomes after cardiac surgery? A propensity analysis

Background: Medicaid patients bear proportionately greater financial responsibility for the cost of outpatient care and medication than non-Medicaid patients. We hypothesized that this difference in provision of continuing care would be associated with adverse clinical outcomes after cardiac surgery. Materials and Methods: In a retrospective cohort analysis, 5056 consecutive adult patients undergoing cardiac surgery at a single institution between 2005 and 2010 were divided according to payer status. Propensity scores were calculated using 16 preoperative and demographic variables for each patient, and 461 1:1 propensity score.matched pairs were analyzed. Patient socioeconomic position was determined using aggregate data derived from zip codes. The main outcome measures were early mortality, postoperative complications, and patient survival. Results: In multivariate analysis, Medicaid was found to be an independent predictor of worse survival after cardiac surgery (hazard ratio [HR], 2.1; 95% confidence interval [CI], 1.2-3.7; P = .01). No significant difference was observed in operative mortality in the 2 groups. After propensity score matching and controlling for socioeconomic position, the only independent predictors of worse midterm survival were an ejection fraction ≤ 30% (HR, 1.7; 95% CI, 1.1-2.7; P = .02) and a higher logistic EuroSCORE (HR, 1.03; 95% CI, 1.0-1.1; P = .02). Conclusions: Comorbidity and lower socioeconomic status appear to be more important predictors of late mortality after cardiac surgery than payer status, which does not have a significant impact on survival.