Racial Disparity in Primary Cesarean Delivery Persists Within Physicians’ Practices: A Multilevel Analysis of Physician Characteristics and Implicit Association Test Results

ObjectiveThe objective of this study was to measure the Black-non-Black gap in primary cesarean delivery at a safetynet hospital and to test whether it varies by the delivering physician's demographics, training, or Implicit Association Test (IAT) result. MethodsThis retrospective cohort study included term, singleton, vertex births without a prior cesarean delivery, at any parity, at a single California safety-net teaching hospital from November 2016 to October 2020.Each birth was linked to the attending physician of record.We fit a multilevel logistic regression model with patients nested within physicians, adjusting for maternal age, BMI, gestational age, parity, and year.We tested physician gender, race, years in practice, training, and race-IAT result as modifiers of the patient-race effect.A physician fixed-effects model estimated the gap within physicians.Nulliparous, term, singleton, vertex (NTSV) births were analyzed as a secondary analysis. ResultsOf 7,249 singleton deliveries, 4,706 births attended by 21 physicians were analyzed.Primary cesarean delivery occurred in 98/478 (20.5%)Black patients and 502/4,228 (11.9%) non-Black patients, and the gap was present in every parity group.The adjusted OR (aOR) was 1.89 (95% CI, 1.47-2.44).In a physician fixedeffects model, it was 1.90 (95% CI, 1.47-2.44)before and 1.88 (95% CI, 1.45-2.42)after accounting for the physician.The disparity did not vary across physicians (random-slope variance estimated at zero), and no physician characteristic modified it (all interaction p ≥ 0.41).Ten of 22 physicians submitted IAT results.The gap was not larger among physicians with a pro-White preference (interaction OR, 0.69; 95% CI, 0.36-1.31); it was present among those with no preference, with primary cesarean delivery occurring in 52/224 (23.2%)Black patients and 236/1,992 (11.8%) non-Black patients.In NTSV births, the aOR was 1.86 (95% CI, 1.24-2.79). ConclusionsA twofold Black-non-Black gap in primary cesarean delivery was present across parity groups and persisted within individual physicians' practices.We found no evidence that it depended on physician demographics or IAT results, although the study could detect only moderate-to-large effects.Our findings point toward patient-, labor management-, and system-level drivers rather than which physician attends the birth.