Association of Race and Family Socioeconomic Status With Pediatric Postoperative Mortality

Abstract

Racial disparities in postoperative outcomes have remained difficult to eliminate. It is commonly understood that socioeconomic status (SES) is an important factor associated with excess risk of postoperative morbidity and death. To date, comparable data exploring the association of family SES with pediatric postoperative mortality are unavailable, and it is unknown whether the advantage provided by higher income status is equitable across racial groups. To assess whether increasing family SES is associated with lower pediatric postoperative mortality and, if so, whether this association is equitable among Black and White children. This retrospective cohort study used data from 51 freestanding pediatric tertiary care hospitals across the US that reported to the Children's Hospital Association Pediatric Health Information System. The study included 1 378 111 Black and White children younger than 18 years who underwent inpatient surgical procedures between January 1, 2004, and December 31, 2020. The exposures of interest were race (Black and White) and parental income quartile (used as a proxy for SES and measured by median income quartile of the zip code of residence). Race was self-reported by parents or guardians at admission or assessed by the registration team consistent with each hospital's policy and state legislation. The primary outcome was risk-adjusted in-hospital mortality rates by race and parental income quartile controlled for baseline covariates. To evaluate whether belonging to the highest income quartile modified the association between race and postoperative mortality, multiplicative and additive interactions were examined. Among 1 378 111 children (773 364 [56.1%] male; mean [SD] age, 7 [6] years) who received inpatient surgical procedures during the study period, 248 464 children (18.0%) were Black, and 1 129 647 children (82.0%) were White; 211 127 children (15.3%) were Hispanic, and 825 477 (59.9%) were non-Hispanic. Only 49 541 Black children (20.3%) belonged to the highest income quartile compared with 482 758 White children (43.0%). The overall mortality rate was 1.2%, and mortality rates decreased as income quartile increased (1.4% in quartile 1 [lowest income], 1.3% in quartile 2, 1.0% in quartile 3, and 0.9% in quartile 4 [highest income]; P < .001). Among those belonging to the 3 lowest income quartiles, Black children had 33% higher odds of postoperative death compared with White children (adjusted odds ratio, 1.33; 95% CI, 1.27-1.39; P < .001). This racial disparity gap persisted among children belonging to the highest income quartile (adjusted odds ratio, 1.39; 95% CI, 1.25-1.54; P < .001). Postoperative mortality rates among Black children in the highest income quartile (1.30%; 95% CI, 1.19%-1.42%) were comparable to those of White children in the lowest income quartile (1.20%; 95% CI, 1.16%-1.25%). The interaction between Black race and income was not statistically significant on either the multiplicative scale (β for interaction = 1.04; 95% CI, 0.93-1.17; P = .45) or the additive scale (relative excess risk due to interaction = 0.01; 95% CI, -0.11 to 0.11; P > .99), suggesting no reduction in the disparity gap across increasing income levels. In this cohort study, increasing SES was associated with lower pediatric postoperative mortality. However, postoperative mortality rates were significantly higher among Black children in the highest SES category compared with White children in the same category, and mortality rates among Black children in the highest SES category were comparable to those of White children in the lowest SES category. These findings suggest that increasing family SES did not provide equitable advantage to Black compared with White children, and interventions that target socioeconomic inequities alone may not fully address persistent racial disparities in pediatric postoperative mortality.