Implementing a Bundle for Evidence-based Cesarean Delivery May Not Be As Beneficial as Expected: A Multi-center, Pre- and Post- Study

Background Standardization of procedures improves outcomes. Though systematic reviews have summarized the evidence-based steps (EBS) of cesarean delivery (CD), their bundled implementation has not been investigated. Objective In this pre- and post-implementation trial, we sought to ascertain if bundled EBS of CD, compared to surgeon’s preference, improves outcomes. Study Design A StaRI (Standards for Reporting Implementation Studies) compliant, multi-center pre- and post-implementation trial at 4 teaching hospitals was conducted. The pre-implementation period consisted of CD done based on the physicians’ preferences for 3 months; educational intervention (e.g., didactics, badge cards, posters, video) occurred at the 4th month. CDs in post-implementation period employed the bundled EBS. A pre-planned 10% randomized audit of both groups assessed adherence and uptake of EBS. The primary outcome was a composite maternal morbidity (CMM), which included estimated blood loss > 1,000 mL, blood transfusion, endometritis, post-partum fever, wound complications, sepsis, thrombosis, ICU admission, hysterectomy, or death. The secondary outcome was a composite neonatal morbidity (CNM) and some of its components were 5-min Apgar score < 7, positive pressure oxygen use, hypoglycemia, or sepsis. A priori Bayesian sample size calculation indicated 700 CD in each group was needed to demonstrate 20% relative reduction (from 15% to 12%) of CMM with 75% certainty. Bayesian logistic regression with neutral priors was used to calculate likelihood of net-improvement in adjusted relative risk (aRR) with 95% credible intervals (CrI). Results A total of 1,425 consecutive CD (721 in pre- and 704 in post-implementation group) were examined. Audited data indicated that the baseline EBS utilization rate during the pre-implementation period was 79%; after the implementation bundled EBS of CD the audited adherence was 89%—an uptake of 10.0% of the EBS. In four aspects, the maternal characteristics differed significantly in the pre- and post-implementation periods: race/ethnicity, hypertensive disorder, and the relative contribution of the 4 centers to the cohorts and the gestational age at delivery, but the indications for CD and whether its duration was < versus > 60 min did not. The rates of CMM in the pre- and post-implementation groups were 26% and 22%, respectively (aRR, 0.88; 95% CrI, 0.73-1.04), with a 94 % Bayesian probability of a reduction in CMM. The CNM occurred in 37% of the pre- and in 41% of the post-implementation group (aRR, 1.12; 95% CrI 0.98-1.39), with a 95% Bayesian probability of worsening in CNM. When CMM were segregated by preterm (<37 wks) and term (> 37 weeks) CD, the improvement in maternal outcomes persisted; when CNM were segregated by gestational age subgroupsthe potential for worsening neonatal outcomes persisted as well. Conclusions Standardization of the evidence-based bundled steps of cesarean delivery resulted in a modest reduction of the composite maternal outcome; however, a paradoxical increase in neonatal composite morbidity was noted. Although individual evidence-based steps may be of value, while awaiting additional intervention trials a formal bundling of such steps is currently not recommended.