Impact of an emergency medicine pharmacist on empiric antibiotic prescribing for pneumonia and intra-abdominal infections.

Purpose: It is critical to engage ED providers in antimicrobial stewardship programs (ASP). Emergency medicine pharmacists (EMPs) play an important role in ASP by working with providers to choose empiric antimicrobials. This study aimed to determine the impact of an EMP on appropriate empiric antibiotic prescribing for community-acquired pneumonia (CAP) and intra-abdominal infections (CA-IAI).

Methods: A retrospective cohort study was conducted evaluating adult patients admitted with CAP or CA-IAI. The primary outcome of this study was to compare guideline-concordant empiric antibiotic prescribing when an EMP was present vs. absent. We also aimed to compare the impact of an EMP in an early-ASP vs. established-ASP.

Results: 320 patients were included in the study (EMP n = 185, no-EMP n = 135). Overall empiric antibiotic prescribing was more likely to be guideline-concordant when an EMP was present (78% vs. 61%, p = 0.001); this was true for both the CAP (95% vs. 79%, p = 0.005) and CA-IAI subgroups (62% vs. 44%, p = 0.025). Total guideline-concordant prescribing significantly increased between the early-ASP and established-ASP (60% vs. 82.5%, p < 0.001) and was more likely when an EMP was present (early-ASP: 68.3% vs. 45.8%, p = 0.005; established-ASP: 90.5% vs. 73.7%, p = 0.005). Patients receiving guideline-concordant antibiotics in the ED continued appropriate therapy upon admission 82.5% of the time vs. 18.8% if the ED antibiotic was inappropriate (p < 0.001).

Conclusion: The presence of an EMP significantly improved guideline-concordant empiric antibiotic prescribing for CAP and CA-IAI in both an early and established ASP. Inpatient orders were more likely to be guideline-concordant if appropriate therapy was ordered in the ED.