ABSTRACT
OBJECTIVE: Regionalization directs patients to high-volume hospitals for specialized care. We investigated regionalization trends and outcomes in pediatric cardiac surgery. DATA SOURCES/STUDY SETTING: Statewide inpatient data from eleven states between 2000 and 2012. STUDY DESIGN: Mortality, length of stay (LOS), and cost were assessed using multivariable hierarchical regression with state and year fixed effects. Primary predictor was hospital case-volume, categorized into low-, medium-, and high-volume tertiles. DATA COLLECTION/EXTRACTION METHODS: We used Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) to select pediatric cardiac surgery discharges. PRINCIPAL FINDINGS: In total, 2841 (8.5 percent), 8348 (25.1 percent), and 22 099 (66.4 percent) patients underwent heart surgeries in low-, medium-, and high-volume hospitals. Mortality decreased over time, but remained higher in low- and medium-volume hospitals. High-volume hospitals had lower odds of mortality and cost than low-volume hospitals (odds ratio [OR] 0.59, P < 0.01, and relative risk [RR] 0.91, P < 0.01, respectively). LOS was longer for high- and medium-volume hospitals, compared to low-volume hospitals (high-volume: RR 1.18, P < 0.01; medium-volume: RR 1.05, P < 0.01). CONCLUSIONS: Regionalization reduced mortality and cost, indicating fewer complications, but paradoxically increased LOS. Further research is needed to explore the full impact on health care utilization.