Structural Factors and Racial Disparities in Severe Maternal Morbidity: An Examination of State-Level Indicators of Structural Racism and Severe Maternal Morbidity Among Black and White Persons in the U.S., 2009-2011

Background: Severe maternal morbidity (SMM) in the United States is increasing, with Black persons experiencing a disproportionate burden of SMM. Racial disparities in SMM unexplained by individual risk factors suggest that structural inequities should be explored as a potential explanation. This study aimed to examine whether exposure to higher levels of structural racism would be associated with higher risk of SMM among Black persons.
Methods: The sample comprised delivery discharge records from the Healthcare Cost and Utilization Project’s (HCUP) Nationwide Inpatient Sample (NIS) during 2009-2011. The sample included n=303,943 deliveries to Black persons and n=1,007,217 deliveries to White persons from 1,087 hospitals in 30 states. The outcome was a composite measure for any SMM during delivery. State-level structural racism was measured by ratios of race-specific population prevalence of six indicators of four domains of structural racism (criminal justice, political participation, education, and employment). Exposure categories were defined by tertiles of indicator ratios. Multilevel adjusted logistic regression models with random intercepts for hospital and state were used to calculate odds ratios (OR) and 95% confidence intervals. Separate models were created for each indicator, first using the combined sample, and then stratified by maternal race.
Results: The average maternal age for all deliveries was 27.8 years. The majority of deliveries without SMM were paid for by private insurance (55.1%) while deliveries with SMM were primarily paid for by Medicare or Medicaid (47.3%). In the combined sample, Black persons had a 1.6 times greater risk of SMM (aOR 1.57, 95% CI: 1.48,1.67) compared to White persons. Among all deliveries, those that occurred in states with the highest level of structural racism as indicated by incarceration and high school graduation rates had lower risk of SMM (aOR 0.78, 95% CI: 0.64, 0.94, and aOR 0.80, 95% CI: 0.71,0.90, respectively) compared to those in states with the lowest level of structural racism. Similar inverse associations between SMM and incarceration and high school graduation rate indicator ratios were observed among White persons (but not Black persons) in stratified models (aOR 0.78, 95% CI: 0.66,0.93 and aOR 0.79, 95% CI: 0.71,0.89 respectively). Black persons giving birth in states with the highest levels of structural racism in the employment domain had significantly lower risk of SMM compared to those with the lowest levels of structural racism (aOR 0.83, 95% CI: 0.71,0.97). Indicator ratios for voter registration, voting, and bachelor’s degrees were not associated with odds of SMM among White or Black persons.
Conclusions: We found that Black persons had a higher risk of SMM during delivery than White persons. White persons had significantly lower risk of SMM in states highest in racial inequality, measured by incarceration and high school graduation rates. Black persons had significantly lower risk of SMM in states highest in racial inequality in employment, measured by managerial occupation rates. Race specific differences in associations between criminal justice, education and employment domains of structural racism suggest areas of focus for public health policies aimed at the reduction of racial disparities in SMM. Future research should focus on refinement of measures of structural racism and develop measures which capture the ways that different domains interact to create and maintain systemic racial inequities.