Systemic racism and Non-Hispanic Black to Non-Hispanic White disparities in infant mortality at the county level

To use a novel measure of systemic racism to examine its relationship with Non-Hispanic Black (NHB) to Non-Hispanic White (NHW) racial disparities in infant mortality across U.S. counties.

In this cross-sectional study, a composite, multi-dimensional measure of systemic racism at the county level was developed using confirmatory factor analysis based on indicators across five dimensions of systemic racism. Using linear regression analysis, we examined the relationship between the systemic racism factor scores and the NHB to NHW racial disparities in county-level infant mortality rates. Additionally, we performed a multi-level analysis of infant mortality, with births nested within counties by running a random intercept model that controlled for factors at both the individual and county levels to take into account the clustered nature of the data.

There were 325 counties that met inclusion criteria for the county level analysis and 1181 counties for the individual level analysis. Each one standard deviation increase in the Systemic Racism Index was associated with an increase of 10.4% in the Non-Hispanic Black to Non-Hispanic White infant mortality rate ratio at the county level (aOR 1.104, 95% CI [1.061-1.148]). After controlling for individual level clinical factors and county level factors, each one standard deviation increase in the systemic racism index score was associated with a decrease of 3.5% in the NHW infant mortality rate (aOR 0.965, 95% CI [0.943-0.988]).

Systemic racism is significantly associated with differences between counties in the magnitude of their Non-Hispanic Black to Non-Hispanic White racial disparities in infant mortality rates.