342 - The Impact of Race and Ethnicity on 1-year Mortality for Congenital Diaphragmatic Hernia

Publication Number: 342.6603

Stephanie M. Tsoi, University of California, San Francisco, School of Medicine, San Francisco, CA, United States; Roberta Keller, UCSF Benioff Children's Hospital San Francisco, San Francisco, CA, United States; Martina Steurer, UCSF Benioff Children's Hospital San Francisco, San Francisco, CA, United States

Background: Congenital diaphragmatic hernia (CDH) occurs in ~2.6 per 10,000 live births, with mortality ~30%.

Objective: In infants with CDH, we sought to: 1) describe the sociodemographic factors, 2) compare 1-year mortality across race/ethnicity and socioeconomic status (SES), and 3) evaluate the contribution of SES and unmeasured factors on mortality disparities by race/ethnicity.

Design/Methods: We used the CDC Natality database to identify all liveborn neonates with CDH in the US from 2014-2019. Maternal and neonatal characteristics and SES were compared between alive and deceased. SES was defined on a graded scale into 3 levels by maternal Medicaid insurance and maternal education. Mortality rates were compared by race/ethnicity and SES. We used logistic regression (adjusted for prematurity, small-for-gestational age, and cyanotic congenital heart disease), and structural equation modeling for mediation analysis (Figure) to assess the influence of SES in the relationship between race/ethnicity and mortality.

Results: 2589 neonates had CDH; 28.4% died in the first year at a mean age of 28 days. Maternal race/ethnicity, education, and Medicaid insurance varied significantly between alive and deceased (Table 1). The overall cause of death other than CDH was respiratory failure. Mortality rate was highest for NHB infants with low SES (41.5%), nearly double that of NHW infants with high SES (21.3%) (Table 2). Mortality odds were significantly higher for infants of NHB and Hispanic mothers: NHB aOR 1.70 (CI 1.29 – 2.24), Hispanic aOR 1.34 (CI 1.07-1.69). Via mediation analyses, SES explained 17.1% (CI 3.2 – 40.5) of the disparity between NHB and NHW mortality, while the unmeasured effects of race were responsible for 75.5% (CI 46.9 - 90.5). In contrast, the effect of SES explained 54.1% (CI 20.4 – 368.6) of the disparity between Hispanic and NHW mortality, while race/ethnicity effects were not significant.

Conclusion(s): CDH 1-year mortality varies significantly across sociodemographic factors, especially SES and Black race. Mediation analyses revealed that the direct effect of race plays a large role in mortality for infants of NHB mothers, while SES plays a large role in mortality for infants of Hispanic mothers. The unmeasured factors that are part of the direct effect of race include social determinants of health, structural and systemic racism, social injustices, and health inequities. This highlights the complex interplay between race/ethnicity and pediatric health outcomes. Further studies must be done to understand the racial and socioeconomic underpinnings of these identified discrepancies in mortality.

Baseline characteristics of neonates and their mothers with congenital diaphragmatic hernia (n=2,589)
Comparison by chi-squared analysis and t-test. Significance at p-value < 0.05. SES variable derived from maternal education (+4 doctoral degree, +3 college/master’s degree, +2 high school degree, +1 less than high school degree) and Medicaid insurance status (-1 present, 0 absent) and classified into 3 groups (0-1 low, 2 middle, 3-4 high).

Mortality rate comparison by race/ethnicity and SES.
Incidence of CDH and mortality rate by race/ethnicity and socioeconomic status compared to overall mortality in each race/ethnicity group (combined score based on maternal education and insurance status).

Mediation analysis between race/ethnicity subgroups and mortality.
Mediation analysis on directed acyclic graph between primary predictor of race (non-Hispanic White compared to non-Hispanic Black, and non-Hispanic White compared to Hispanic) and primary outcome (mortality) with mediators showing a statistically significant association (logistic regression p-value < 0.05) between predictor and outcome. Values on arrows represent the percentage attributed (95% confidence interval) to that labeled relationship for the difference in mortality rate between the race/ethnicity comparison. * denotes significance at p-value < 0.05.

Baseline characteristics of neonates and their mothers with congenital diaphragmatic hernia (n=2,589)
Comparison by chi-squared analysis and t-test. Significance at p-value < 0.05. SES variable derived from maternal education (+4 doctoral degree, +3 college/master’s degree, +2 high school degree, +1 less than high school degree) and Medicaid insurance status (-1 present, 0 absent) and classified into 3 groups (0-1 low, 2 middle, 3-4 high).

Mortality rate comparison by race/ethnicity and SES.
Incidence of CDH and mortality rate by race/ethnicity and socioeconomic status compared to overall mortality in each race/ethnicity group (combined score based on maternal education and insurance status).

Mediation analysis between race/ethnicity subgroups and mortality.
Mediation analysis on directed acyclic graph between primary predictor of race (non-Hispanic White compared to non-Hispanic Black, and non-Hispanic White compared to Hispanic) and primary outcome (mortality) with mediators showing a statistically significant association (logistic regression p-value < 0.05) between predictor and outcome. Values on arrows represent the percentage attributed (95% confidence interval) to that labeled relationship for the difference in mortality rate between the race/ethnicity comparison. * denotes significance at p-value < 0.05.