Disparities in Congenital Heart Disease Mortality Based on Proximity to a Specialized Pediatric Cardiac Center
Authors: Jonathan R. Kaltman, Kristin M. Burns, Gail D. Pearson, David C. Goff, Frank Evans
Journal: Circulation (2020)

acial and socioeconomic disparities exist in congenital heart disease-related infant mortality (CHD-IM).Blacks and infants of mothers with Medicaid insurance or greater poverty experience worse outcomes. 1,2In the United States, the expertise and resources to manage complex patients with congenital heart disease (CHD) are concentrated typically at specialized pediatric cardiac centers (PCCs) located in metropolitan areas.We hypothesize that a further source of disparity is the proximity of a family's residence to a specialized PCC.We tested this hypothesis using a cross-sectional, population-based sample of linked birth/infant death data files from the National Center for Health Statistics at the Centers for Disease Control and Prevention 3 containing live births from 2011 through 2015.All deaths of infants (<365 days of age) born to US residents in a given year are included.The outcome was death attributable to CHD as the underlying cause on the death certificate, based on International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes Q20.0 through Q28.9.The main exposure was proximity to 1 of 50 top PCCs (PCC-T50) per the US News & World Report in 2017. 4The threshold of 50 was chosen because US News & World Report ranks only 50 centers.The exposure variable was defined dichotomously based on whether the maternal residence was in a metropolitan area with at least one PCC-T50.CHD-IM (per 1000 live births) was determined for infants whose mothers lived proximal to a PCC-T50 versus those who did not.CHD-IM was also determined for infants whose mothers lived in a metropolitan area with a PCC not among the PCC-T50.Unadjusted CHD-IM (95% CIs) was calculated by proximity for each stratum of sex, maternal race/ethnicity, birth weight, gestational age, maternal education, and insurance payment method for delivery.Unadjusted associations were evaluated using the χ 2 test.Poisson regression provided estimated rate ratios comparing CHD-IM for infants whose mothers lived proximal to a PCC-T50 versus those who did not, adjusted for sex, gestational age, maternal race/ethnicity, maternal education, and insurance.Birth weight was collinear with gestational age and was excluded from the final model.As a sensitivity analysis, Poisson regression was repeated for infants who died of critical CHD 5 (CCHD) and of non-CCHD.This was not human subjects research, and, thus, no institutional review board approval was obtained.From 2011 through 2015, the unadjusted CHD-IM rate was 0.33/1000 live births (6532 CHD-related deaths/19 849 688 live births).CHD-IM rates varied by covariate strata (Table ).All PCC-T50s were located in metropolitan areas (n=46).Mothers' residential proximity to a PCC could not be determined from the records of 44 503 (0.2%) live births.For mothers living proximal to a PCC-T50, the unadjusted CHD-IM rate was 0.28/1000 live births (2601 deaths/9 253 660 live births) in comparison with a CHD-IM rate of 0.37/1000 live births (3918 deaths/