Hospital contribution to variation in rates of vaginal birth after cesarean

OBJECTIVE: To determine the influence of delivery hospital on the rate of vaginal birth after cesarean (VBAC). STUDY DESIGN: This retrospective cohort study used claims data from Blue Cross and Blue Shield of Michigan. Women with a prior cesarean and a singleton livebirth between 2012 and 2016 were included. We calculated the hospital-specific risk-standardized VBAC rates and median odds ratio as a measure of variation. RESULT: Hospital-level adjusted rates varied nearly 10-fold (3.7%-35.5%). Compared to the lowest volume hospitals (1(st) quartile), the likelihood of VBAC increased for those in the 2(nd) (adjusted OR 2.75 [95% CI 1.23-6.17]), 3(rd) (adjusted OR 3.73 [95% CI 1.59-8.75]), and 4(th) quartiles (adjusted OR 2.9 [95% CI 1.11-7.72]). The median OR suggested significant variation by hospital after adjustment. CONCLUSION: The delivery hospital itself explains a large amount of the variation in rates of VBAC after adjustment for patient and hospital characteristics.