Challenges and Opportunities of Using a National Database to Evaluate Racial/Ethnic Disparities and Breastfeeding Effects on Sudden Unexpected Infant Death.

Background: Sudden unexpected infant death (SUID) rates remain higher in American Indian/Alaska Native (AI/AN) and non-Hispanic Black (NHB) infants than other demographic groups. Racial disparities are also evident in breastfeeding, which is associated with reduced risk of SUID. Objective: To assess the relationship between racial/ethnic disparities in SUID and breastfeeding beyond the newborn period using U.S. nationally reported public databases. Methods: Data were extracted from Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (WONDER) and the National Immunization Surveys (NISs) 2009-2017. WONDER data were restricted to full-term infants and sorted by death year, race/ethnicity, and other characteristics. NIS breastfeeding data included ever breastfed, breastfed at 6 months, and exclusive breastfeeding at 3 and 6 months. Breastfeeding rates and mortality data were aggregated based on race/ethnicity, and mortality rates were analyzed by weighted (number of births) multivariable linear regression. Results: SUID rates were highest among NHB and AI/AN infants who also had the lowest breastfeeding rates. When breastfeeding and race/ethnicity were included in the analyses, race/ethnicity confounded the relationship between breastfeeding and SUID. When race was excluded, ever breastfeeding and any breastfeeding at 6 months were associated with significantly decreased SUID rates. Conclusion: Race/ethnicity confounded the relationship between breastfeeding and SUID. Analysis was limited because individual SUID rates were available for maternal/birth characteristics but not for breastfeeding. Our study showed a need for adding additional data points to other national databases to better understand the role that breastfeeding plays in the racial/ethnic disparities in SUID.