Hospital-level variation in racial disparities in low-risk nulliparous cesarean delivery rates

<bold>Background: </bold>Nationally, rates of cesarean delivery are highest among Black patients compared with other racial/ethnic groups. These observed inequities are a relatively new phenomenon (in the 1980s, cesarean delivery rates among Black patients were lower than average), indicating an opportunity to narrow the gap. Cesarean delivery rates vary greatly among hospitals, masking racial disparities that are unseen when rates are reported in aggregate.<bold>Objective: </bold>This study aimed to explore reasons for the current large Black-White disparity in first-birth cesarean delivery rates by first examining the hospital-level variation in first-birth cesarean delivery rates among different racial/ethnic groups. We then identified hospitals that had low first-birth cesarean delivery rates among Black patients and compared them with hospitals with high rates. We sought to identify differences in facility or patient characteristics that could explain the racial disparity.<bold>Study design: </bold>A population cross-sectional study was performed on 1,267,493 California live births from 2018 through 2020 using birth certificate data linked with maternal patient discharge records. Annual nulliparous term singleton vertex cesarean delivery (first-birth) rates were calculated for the most common racial/ethnic groups statewide and for each hospital. Self-identified race/ethnicity categories as selected on the birth certificate were used. Relative risk and 95% confidence intervals for first-birth cesarean delivery comparing 2019 with 2015 were estimated using a log-binomial model for each racial/ethnic group. Patient and hospital characteristics were compared between hospitals with first-birth cesarean delivery rates <23.9% for Black patients and hospitals with rates >= 23.9% for Black patients.<bold>Results: </bold>Hospitals with at least 30 nulliparous term singleton vertex Asian, Black, Hispanic, and White patients each were identified. Black patients had a very different distribution, with a significantly higher rate (28.4%) and wider standard deviation (7.1) and interquartile range (6.5) than other racial groups (P<.01). A total of 29 hospitals with a low first-birth cesarean delivery rate among Black patients were identified using the Healthy People 2020 target of 23.9% and compared with 106 hospitals with higher rates. The low-rate group had a cesarean delivery rate of 19.9%, as opposed to 30.7% in the higher-rate group. There were no significant differences between the groups in hospital characteristics (ownership, delivery volume, neonatal level of care, proportion of midwife deliveries) or patient characteristics (age, education, insurance, onset of prenatal care, body mass index, hypertension, diabetes mellitus). Among the 106 hospitals that did not meet the target for Black patients, 63 met it for White patients with a mean rate of 21.4%. In the same hospitals, the mean rate for Black patients was 29.5%. Among Black patients in the group that did not meet the 23.9% target, there were significantly higher rates of all cesarean delivery indications: labor dystocia, fetal concern (spontaneous labor), and no labor (eg, macrosomia), which are all indications with a high degree of subjectivity.<bold>Conclusion: </bold>The statewide cesarean delivery rate of Black patients is significantly higher and has substantially greater hospital variation compared with other racial or ethnic groups. The lack of difference in facility or patient characteristics between hospitals with low cesarean delivery rates among Black patients and those with high rates suggests that unconscious bias and structural racism potentially play important roles in creating these racial differences.