Volume 54 | Number 4 | August 2019

Abstract List

Rie Sakai‐Bizmark MD, MPH, PhD, Laurie A. Mena MS, Hiraku Kumamaru M.D., ScD., Ichiro Kawachi M.D., Ph.D., Emily H. Marr PhD, Eliza J. Webber MPH, Hyun H. Seo BA, Scott I. M. Friedlander MPH, Ruey‐Kang R. Chang MD, MPH


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 (), 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 (‐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 [] 0.59, <0.01, and relative risk [] 0.91, <0.01, respectively). was longer for high‐ and medium‐volume hospitals, compared to low‐volume hospitals (high‐volume: 1.18, <0.01; medium‐volume: 1.05, <0.01).


Regionalization reduced mortality and cost, indicating fewer complications, but paradoxically increased . Further research is needed to explore the full impact on health care utilization.