Cohort Selection and the Estimation of Racial Disparity in Mortality of Extremely Preterm Neonates

Overview

Journal Pediatr Res

Specialties Biology
Pediatrics

Date 2023 Aug 14

PMID 37580552

Authors

Jeffrey B Gould

Mihoko V Bennett

Jochen Profit

Henry C Lee

Affiliations

Soon will be listed here.

Abstract

Background: Racial disparities in preterm neonatal mortality are long-standing. We aimed to assess how cohort selection influences mortality rates and racial disparity estimates.

Methods: With 2014-2018 California data, we compared neonatal mortality rates among Black and non-Hispanic White very low birth weight (VLBW, <1500 g) or very preterm infants (22-29 weeks gestational age). Relative risks were estimated by different cohort selection criteria. Blinder-Oaxaca decomposition quantified factors contributing to mortality differential.

Results: Depending upon standard selection criteria, mortality ranged from 6.2% (VLBW infants excluding first 12-h deaths) to 16.0% (22-29 weeks' gestation including all deaths). Black observed neonatal mortality was higher than White infants only for delivery room deaths in VLBW infants (5.6 vs 4.2%). With risk adjustment accounting for higher rate of low gestational age, low Apgar score and other factors, White infant mortality increased from 15.9 to 16.6%, while Black infant mortality decreased from 16.7 to 13.7% in the 22-29 weeks cohort. Across varying cohort selection, risk adjusted survival advantage among Black infants ranged from 0.70 (CL 0.61-0.80) to 0.84 (CL 0.76-0.93).

Conclusions: Standard cohort selection can give markedly different mortality estimates. It is necessary to reduce prematurity rates and perinatal morbidity to improve outcomes for Black infants.

Impact: In this population-based observational cohort study that encompassed very low birth weight infant hospitalizations in California, varying standard methods of cohort selection resulted in neonatal mortality ranges from 6.2 to 16.0%. Across all cohorts, the only significant observed Black-White disparity was for delivery room deaths in Very Low Birth Weight births (5.6 vs 4.2%). Across all cohorts, we found a 16-30% survival advantage for Black infants. Cohort selection can result in an almost three-fold difference in estimated mortality but did not have a meaningful impact on observed or adjusted differences in neonatal mortality outcomes by race and ethnicity.

Citing Articles

Methodologic considerations in estimating racial disparity of mortality among very preterm infants.

Jiang S, Rose L, Gould J, Bennett M, Profit J, Lee H Pediatr Res. 2024; .

PMID: 39179872 DOI: 10.1038/s41390-024-03485-w.

References

Beck A, Edwards E, Horbar J, Howell E, McCormick M, Pursley D . The color of health: how racism, segregation, and inequality affect the health and well-being of preterm infants and their families. Pediatr Res. 2019; 87(2):227-234. PMC: 6960093. DOI: 10.1038/s41390-019-0513-6. View

Travers C, Carlo W, McDonald S, Das A, Ambalavanan N, Bell E . Racial/Ethnic Disparities Among Extremely Preterm Infants in the United States From 2002 to 2016. JAMA Netw Open. 2020; 3(6):e206757. PMC: 7287569. DOI: 10.1001/jamanetworkopen.2020.6757. View

Richardson D, Tarnow-Mordi W, Lee S . Risk adjustment for quality improvement. Pediatrics. 1999; 103(1 Suppl E):255-65. View

Forner O, Schiby A, Ridley A, Thiriez G, Mugabo I, Morel V . Extremely premature infants: How does death in the delivery room influence mortality rates in two level 3 centers in France?. Arch Pediatr. 2018; 25(6):383-388. DOI: 10.1016/j.arcped.2018.06.006. View

Anderson J, Rogers E, Baer R, Oltman S, Paynter R, Partridge J . Racial and Ethnic Disparities in Preterm Infant Mortality and Severe Morbidity: A Population-Based Study. Neonatology. 2017; 113(1):44-54. DOI: 10.1159/000480536. View

Ely D, Driscoll A . Infant Mortality in the United States, 2020: Data From the Period Linked Birth/Infant Death File. Natl Vital Stat Rep. 2022; 71(5):1-18. View

Gage T, Fang F, ONeill E, DiRienzo A . Racial disparities in infant mortality: what has birth weight got to do with it and how large is it?. BMC Pregnancy Childbirth. 2010; 10:86. PMC: 3025864. DOI: 10.1186/1471-2393-10-86. View

Lee M, Hall E, DeFranco E . Contribution of previable births to infant mortality rate racial disparity in the United States. J Perinatol. 2019; 39(9):1190-1195. DOI: 10.1038/s41372-019-0394-x. View

Morisaki N, Isayama T, Samura O, Wada K, Kusuda S . Socioeconomic inequity in survival for deliveries at 22-24 weeks of gestation. Arch Dis Child Fetal Neonatal Ed. 2017; 103(3):F202-F207. DOI: 10.1136/archdischild-2017-312635. View

10.

Koller-Smith L, Shah P, Ye X, Sjors G, Wang Y, Chow S . Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants. BMC Pediatr. 2017; 17(1):166. PMC: 5512978. DOI: 10.1186/s12887-017-0921-x. View

11.

Kramer M, Ananth C, Platt R, Joseph K . US Black vs White disparities in foetal growth: physiological or pathological?. Int J Epidemiol. 2006; 35(5):1187-95. DOI: 10.1093/ije/dyl125. View

12.

Rahimi E, Hashemi Nazari S . A detailed explanation and graphical representation of the Blinder-Oaxaca decomposition method with its application in health inequalities. Emerg Themes Epidemiol. 2021; 18(1):12. PMC: 8343972. DOI: 10.1186/s12982-021-00100-9. View

13.

DeSisto C, Hirai A, Collins Jr J, Rankin K . Deconstructing a disparity: explaining excess preterm birth among U.S.-born black women. Ann Epidemiol. 2018; 28(4):225-230. DOI: 10.1016/j.annepidem.2018.01.012. View

14.

Benmarhnia T, Huang J, Basu R, Wu J, Bruckner T . Decomposition Analysis of Black-White Disparities in Birth Outcomes: The Relative Contribution of Air Pollution and Social Factors in California. Environ Health Perspect. 2017; 125(10):107003. PMC: 5933346. DOI: 10.1289/EHP490. View

15.

Reid L, Weiss A, Fingar K . Contributors to disparities in postpartum readmission rates between safety-net and non-safety-net hospitals: A decomposition analysis. J Hosp Med. 2022; 17(2):77-87. DOI: 10.1002/jhm.2769. View

16.

Iceland J . Racial and Ethnic Inequality in Poverty and Affluence, 1959-2015. Popul Res Policy Rev. 2019; 38(5):615-654. PMC: 6934366. DOI: 10.1007/s11113-019-09512-7. View

17.

Janevic T, Zeitlin J, Auger N, Egorova N, Hebert P, Balbierz A . Association of Race/Ethnicity With Very Preterm Neonatal Morbidities. JAMA Pediatr. 2018; 172(11):1061-1069. PMC: 6248139. DOI: 10.1001/jamapediatrics.2018.2029. View

18.

Joseph K, Kramer M . The fetuses-at-risk approach: survival analysis from a fetal perspective. Acta Obstet Gynecol Scand. 2017; 97(4):454-465. PMC: 5887948. DOI: 10.1111/aogs.13194. View

19.

Whitcomb B, Schisterman E, Perkins N, Platt R . Quantification of collider-stratification bias and the birthweight paradox. Paediatr Perinat Epidemiol. 2009; 23(5):394-402. PMC: 2743120. DOI: 10.1111/j.1365-3016.2009.01053.x. View

20.

Basso O . Implications of Using a Fetuses-at-Risk Approach When Fetuses Are Not at Risk. Paediatr Perinat Epidemiol. 2016; 30(1):3-10. DOI: 10.1111/ppe.12254. View