Establishing obstetrics-specific metrics and interventions for antimicrobial stewardship

Background: To describe baseline antimicrobial stewardship (AMS) metrics and apply AMS interventions in an inpatient obstetrical population. Methods: From October 2018 to October 2019, our tertiary-care obstetrical center reviewed components of our AMS program, which included: (1) antimicrobial consumption data, (2) point prevalence surveys (PPS), and (3) prospective audit and feedback. We reviewed institutional data for antimicrobial consumption from the pharmacy database. Detailed point prevalence surveys were conducted for all antimicrobial prescriptions on two predefined dates each month. Daily audits and feedback assessed the appropriateness of all non-protocolized antimicrobials. Results: Our average antimicrobial length of therapy (LOT) was 12 days per 100 patient-days, where erythromycin (2.33), amoxicillin (2.28), and ampicillin (1.81) were the greatest contributors. Point prevalence surveys revealed that 28.8% of obstetrical inpatients were on antimicrobials, of which 11.2% were inappropriate. Protocolized antimicrobials were 62% less likely ( p = 0.027) to be inappropriate. From 565 audited prescriptions, 110 (19.5%) resulted in feedback, where 90% of recommendations were accepted and implemented. The most common reasons for interventions include incorrect dosage, recommending a diagnostic test before continuing antimicrobials, and changing antimicrobials based on specific culture and sensitivity. Conclusions: Antimicrobial use in obstetrics is unique compared to general inpatients. We provide a baseline set of metrics for AMS at our obstetrical center intending to lay the groundwork for AMS programming in our discipline. Antimicrobial protocolization, as well as audit and feedback, are feasible interventions to improve antimicrobial prescribing patterns.