Impact of order set implementation on appropriate treatment of community-acquired pneumonia (CAP)

Objective: This study aimed to evaluate appropriate antimicrobial prescribing after implementing a pneumonia order set within a community teaching hospital. Design: Retrospective chart review study. Setting: 450-bed community teaching hospital. Participants: Patients who are 18 years of age or older admitted for treatment of community-acquired pneumonia (CAP) between October 1, 2021, and August 1, 2023. Methods: This retrospective cohort study aimed to evaluate a composite endpoint of appropriate empiric antimicrobial selection, dosing, and duration in accordance with the national guidelines after the implementation of a CAP order set. Secondary outcomes included comparing hospital length of stay (LOS), readmission rates, mortality rates, and Clostridium difficile infection rates. Results: A total of 236 patients were included (118 patients per group). Significantly more patients in the post-implementation group received guideline-concordant therapy for CAP (5.9% vs 35.6%, P < .001). Results were heavily influenced by improvements in appropriate durations of therapy (pre: 6.8% vs post: 39.9%, P < .001). There were no significant differences observed for LOS, 30-day readmission rates, C. difficile infections within 30 days, or mortality rates between groups. The order set was utilized in 66.1% of patients included in the post-implementation group. Conclusions: Implementing an order set significantly improved inpatient antibiotic prescribing for CAP with no difference in clinical or safety outcomes. Antibiotic order sets will be a useful tool for antimicrobial stewardship program expansion into other common community-acquired infections.