Fidelity to individual components of a standardized labor induction protocol and association with improved obstetric outcomes: secondary analysis of a randomized controlled trial

Background Standardized labor induction protocols improve obstetric outcomes. However, these protocols are complex. The Consolidated Framework for Implementation Research describes intervention components as “core” and “adaptable periphery.” We aimed to identify core components by investigating the individual components of an evidence-based protocol most associated with effectiveness. We planned to utilize this information to simplify our protocol prior to multi-site implementation. Methods This is a secondary analysis of an RCT comparing time to delivery among four labor induction methods. All patients enrolled in the trial had their labor managed with a multidisciplinary-developed, evidence-based labor induction protocol. For each patient’s induction, we assessed fidelity to 7 components of the protocol. Primary effectiveness outcomes included cesarean delivery, maternal morbidity, and neonatal morbidity. Bivariate analyses assessed association of each component with each primary effectiveness outcome. Multivariable logistic regression determined independent predictors of each outcome while controlling for demographic and clinical factors known to be related to our outcomes. Results The 491 patients enrolled in the RCT were included in this analysis. While multiple components were associated with each outcome in bivariate analysis, few were found to be independent predictors of effectiveness in multivariable analysis. For cesarean delivery, only one component “for women in active labor, all cervical exams were performed ≤2.5 hours apart” was an independent predictor. For maternal morbidity, only one “if an intracervical Foley catheter was utilized for cervical ripening, it was removed within 12 hours of placement” remained significant. For neonatal morbidity, two components “all cervical exams performed in latent labor were performed ≤4.5 hours apart” and “for women in active labor, all cervical exams were performed ≤2.5 hours apart” remained independent predictors. Of the independent predictors of effectiveness, most reflected the overarching concept of “frequent exams in labor will allow for more frequent intervention when no change is made”.Conclusions This study demonstrates a novel strategy to identify which components of an evidence-based intervention should be “core” and which are “adaptable periphery”; this provides valuable information when designing for dissemination and implementation. With an understanding of the relationship between fidelity to individual protocol components and effectiveness, we can systematically simplify interventions prior to large-scale implementation, a potential strategy to increase implementation success. These data will be used to streamline our protocol to best target cesarean rate and maternal/neonatal morbidity prior to a planned type I hybrid effectiveness-implementation trial.