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 tenfold (3.7%-35.5%). Compared to the lowest volume hospitals (1st quartile), the likelihood of VBAC increased for those in the 2nd (adjusted OR 2.75 [95% CI 1.23-6.17]), 3rd (adjusted OR 3.73 [95% CI 1.59-8.75]), and 4th 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.