Kochilas, Lararos K.2014-09-092014-09-092012-06https://hdl.handle.net/11299/165553University of Minnesota M.S. thesis. June 2012. Major: Clinical Research. Advisor: William Thomas. 1 computer file (PDF); vii, 33 pages.Context: Mortality after pediatric cardiac surgery varies substantially among centers, but the impact of center-specific effects remains poorly understood. Objective: To assess the impact of surgical volume and other center effects on early mortality after pediatric cardiac surgery. Design, Setting, Participants: Retrospective cohort study utilizing risk-adjusted outcome data from the Pediatric Cardiac Care Consortium, a consortium of small and medium size North American centers (<500 cases/year). Hierarchical multivariate logistic regression analysis was used to assess the impact of surgical volume and center effects over time. Main outcome measure: Risk-adjusted early post-operative mortality. Results: From 1982 to 2007, 49 centers reported 109,447 operations. Patient characteristics varied significantly among centers. The adjusted odds ratio (OR) for mortality decreased more than 10-fold over the study period (1982 vs. 2007 OR 12.27, 95% CI: 8.52-17.66, p<0.001). Surgical volume was inversely associated with odds of death (additional 100 cases/year OR 0.84, 95% CI: 0.78-0.90, p<0.001). The volume effect was fairly consistent across age groups, risk categories (except the lowest), and time periods. Risk category was the most significant predictor of mortality, while time period, patient age, and a volume-independent center effect had additional weak effects. Conclusions: Mortality after pediatric cardiac operations has decreased significantly over the last 25 years. RACHS-1 risk category remains the strongest predictor of post-operative mortality. Center-specific variation exists and is only partially explained by operative volume. Low-risk pediatric cardiac surgery is safely performed at centers performing fewer than 200 cases/year; regionalization or other quality-improvement strategies may be warranted for complex cases.en-USThesis or Dissertation