Abstract
Objectives
We examined the relationship between income inequality and the risk for infant/neonatal mortality at the state and county level and tested possible mediators of this relationship.
Methods
We first linked state and county Gini coefficients to US Vital Statistics 2010 Cohort Linked Birth and Infant Death records (n = 3,954,325). We then fit multilevel models to test whether income inequality was associated with infant/neonatal mortality. County-level factors were tested as potential mediators.
Results
Adjusted analyses indicated that income inequality at the county level—but not at the state level—was associated with increased odds of infant mortality (OR 1.14, 95% CI 1.10, 1.18) and neonatal death (OR 1.17, 95% CI 1.12, 1.23). Our mediators explained most of this variation. Bivariate analyses revealed associations between 3 county-level measures—patient-to-physician ratio, the violent crime rate, and sexually transmitted infection rate—and infant and neonatal mortality. Proportion of college-educated adults was associated with decreased odds for neonatal mortality.
Conclusions
Local variations in access to care, the rate of sexually transmitted disease, and crime are associated with infant mortality, while variations in college education in addition to these mediators explain neonatal mortality. To reduce infant and neonatal mortality, experiments are needed to examine the effectiveness of policies targeted at reducing income inequality and improving healthcare access, policing, and educational opportunities.
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Acknowledgements
Funding for this study was provided by the National Institutes of Health Research, National Institute on Minority Health and Health Disparities (1R15MD010223-01). Roman Pabayo is a Tier II Canada Research Chair in social and health inequities throughout the lifespan. The investigators would like to thank the undergraduate interns who worked on this project: Ishrat Haque, Anthony Omaye, Kyle Riley, and Janiria Robinson.
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Amy Ehntholt declares that she has no conflict of interest. Daniel Cook declares that he has no conflict of interest. Natalie Rosenquist declares she has no conflict of interest. Peter Muennig declares he has no conflict of interest. Roman Pabayo declares he has no conflict of interest.
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Ehntholt, A., Cook, D.M., Rosenquist, N.A. et al. State- and county-level income inequality and infant mortality in the USA in 2010: a cohort study. Int J Public Health 65, 769–780 (2020). https://doi.org/10.1007/s00038-020-01388-1
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DOI: https://doi.org/10.1007/s00038-020-01388-1