Association between race/ethnicity, illness severity, and mortality in children undergoing cardiac surgery.

OBJECTIVE:Prior studies demonstrate an association between nonwhite race/ethnicity, insurance status, and mortality after pediatric congenital heart surgery. The influence of severity of illness on that association is unknown. We examined the relationship between race/ethnicity, severity of illness, and mortality in congenital cardiac surgery, and whether severity of illness is a mechanism by which nonwhite patients experience increased surgical mortality. METHODS:We performed a retrospective cohort study of children younger than age 18 years old undergoing cardiac surgery admitted to the intensive care unit (n = 40,545) between 2009 and 2016 from the Virtual Pediatric Systems (VPS, LLC, Los Angeles, Calif) database. Multivariate regression models were constructed to examine the role of severity of illness as a mediator between race/ethnicity and mortality in children undergoing cardiac surgery. RESULTS:In multivariate models examining severity of illness scores, African-American patients had statistically significant higher severity of illness scores when compared with their white counterparts. In multivariate models of intensive care unit mortality after adjustment for covariates, African-American patients had a higher odds of postoperative mortality (odds ratio, 1.40, 95% confidence interval, 1.04-1.89) when compared with white children. This increased odds of mortality was mediated through higher severity of illness, because adjustment for severity of illness removed this survival disadvantage for black patients. CONCLUSIONS:Although African-American children undergoing cardiac surgery had higher postoperative mortality, this survival difference appears to be mediated via severity of illness. Preoperative and intraoperative factors may be drivers for this survival disparity.