Hospital surgical volume–outcome relationship in caesarean hysterectomy for placenta accreta spectrum

Objective To examine the association between hospital surgical volume of caesarean hysterectomy and surgical morbidity in women with placenta accreta spectrum (PAS). Design Population‐based retrospective cohort study. Setting National Inpatient Sample, January 2016 to December 2018. Population Six thousand and ten women with PAS who underwent caesarean hysterectomy in 738 centres. Methods (1) Comprehensive modelling for relative hospital surgical volume cut‐point selection, (2) multinomial regression analysis for characterising hospital surgical volume, and (3) binary logistic regression analysis to examine the volume–outcome relationship. Main outcome measures Surgical morbidity (haemorrhage, coagulopathy, shock, urinary tract injury, and death). Results The majority of centres had five surgeries over the 3‐year period (468 centres, 63.4%) and were grouped as the low‐volume group. Surgical morbidity decreased after a relative hospital surgical volume of 25 cases (24 centres, 3.3%) was reached, grouped as the high‐volume group. The remaining centres were grouped as the mid‐volume group (246 centres, 33.3%). In multivariable analysis, women in the high‐volume group were more likely to be Black, have lower median household income, medical comorbidity, previous caesarean delivery, placenta praevia or placenta percreta, and to have undergone surgeries at large urban teaching hospitals compared with those in the low‐volume group (all, P