Volume Alone Does Not Predict Quality Outcomes in Hospitals Performing Pediatric Cardiac Surgery.

ABSTRACT

BACKGROUND: Lower institutional volume has been associated with inferior pediatric cardiac surgery outcomes. This study explored the variation in mortality rates among low-, mid-, and high-volume hospitals performing pediatric cardiac surgery in the United States. METHODS: The Kids' Inpatient Database was explored for the years 2016 and 2019. Hospitals performing only off-bypass coarctation and ventricular septal defect repair were omitted. The hospitals were divided into 3 groups by their annual case volume. Multivariable logistic regression models were fit to obtain risk-adjusted in-hospital mortality rates. RESULTS: A total of 25,749 operations performed by 235 hospitals were included in the study. The risk-adjusted mortality rate for the entire sample was 1.9%. There were 140 hospitals in the low-volume group, 64 hospitals in the mid-volume group, and 31 in the high-volume group. All groups had low-mortality (mortality <1.9%) and high-mortality (mortality >1.9%) hospitals. Among low-volume hospitals, 53% were low-mortality (n = 74) and 47% were high-mortality (n = 66) hospitals. Among mid-volume hospitals, 58% were low-mortality (n = 37) and 42% were high-mortality (n = 27) hospitals. Among high-volume hospitals, 68% were low-mortality (n = 21) and 32% were high-mortality (n = 10) hospitals. There was no statistically significant difference in risk-adjusted in-hospital mortality when comparing low-, mid-, and high-volume centers for 7 Society of Thoracic Surgeons benchmark procedures. CONCLUSIONS: This national, real-world, risk-adjusted volume outcome analysis highlights that volume alone may not be the sole arbiter to predict quality of pediatric cardiac surgery outcomes. Using case volume alone as a surrogate for quality may unfairly asperse high-performing, low-volume programs.