Low-risk Cesareans Across the US: A Decomposition of Individual- and County-level Factors by Race/Ethnicity

Non-Hispanic (NH) Black birthing persons show the highest prevalence of low-risk cesareans (30.8%), compared to NH White birthing persons (25.3%). Individual, as well as place-based and ecological factors, may contribute to this racial disparity. We examine individual- and county-level characteristics that contribute to the racial disparity, as well as the extent to which the disparity can be attributed to differences in measured characteristics of racial groups. We retrieved data on all live births in the US, between 1998 to 2018, from natality files assembled by the National Center of Health Statistics Division of Vital Statistics. We conduct an Oaxaca-Blinder decomposition of all low-risk births (> 11 million) from all counties in the US. We find that differences in measured characteristics comprise 47.5% of the racial disparity. Older maternal age, higher birthweight percentile, and unmarried status contribute the greatest towards widening the disparity, whereas contextual factors, such as county-level poverty and education, play a more complex and nuanced role. Given that over half of the disparity remains unexplained, it indicates that unmeasured differences - either due to treatment of racial groups, patient preferences, or other healthcare supply-side factors - could play a significant role. Future research should investigate additional antecedents of low-risk cesareans among NH Black birthing persons.