Background: Racial inequities in congenital heart disease (CHD) outcomes are well documented, but contributing factors warrant further investigation. We examined the interplay between race, socioeconomic position, and neonatal variables (prematurity and small for gestational age) on 1-year death in infants with CHD. We hypothesize that socioeconomic position mediates a significant part of observed racial disparities in CHD outcomes.
Methods: Linked birth/death files from the Natality database for all liveborn neonates in the United States were examined from 2014 to 2018. Infants with cyanotic CHD were identified. Non-Hispanic Black (NHB) and Hispanic infants were compared with non-Hispanic White (NHW) infants. The primary outcome was 1-year death. Socioeconomic position was defined as maternal education and insurance status. Variables included as mediators were prematurity, small for gestational age, and socioeconomic position. Structural equation modeling was used to calculate the contribution of each mediator to the disparity in 1-year death.
Results: We identified 7167 NHW, 1393 NHB, and 1920 Hispanic infants with cyanotic CHD. NHB race and Hispanic ethnicity were associated with increased 1-year death compared to NHW (OR, 1.43 [95% CI, 1.25-1.64] and 1.17 [95% CI, 1.03-1.33], respectively). The effect of socioeconomic position explained 28.2% (CI, 15.1-54.8) of the death disparity between NHB and NHW race and 100% (CI, 42.0-368) of the disparity between Hispanic and NHW. This was mainly driven by maternal education (21.3% [CI, 12.1-43.3] and 82.8% [CI, 33.1-317.8], respectively) while insurance status alone did not explain a significant percentage. The direct effect of race or ethnicity became nonsignificant: NHB versus NHW 43.1% (CI, -0.3 to 63.6) and Hispanic versus NHW -19.0% (CI, -329.4 to 45.3).
Conclusions: Less privileged socioeconomic position, especially lower maternal education, explains a large portion of the 1-year death disparity in Black and Hispanic infants with CHD. These findings identify targets for social interventions to decrease racial disparities.
Keywords: cyanotic congenital heart disease; heart disease; infant mortality; racial disparity; socioeconomic status.