Effectiveness of Noncertified Pharmacist–Led Antimicrobial Stewardship Programs in a Medium-Sized Hospital Without an Infectious Disease Specialist: A Retrospective Pre–Post Study

BACKGROUND: Few studies have reported the outcomes of antimicrobial stewardship programs (ASPs) implemented without infectious disease (ID) physician or pharmacist specialists. We implemented interventions that included providing antimicrobial optimization recommendations through a pharmacist-led team using prospective audit and feedback. This study evaluated different types of interventions and their impact on the outcomes of ASPs in a medium-sized hospital without ID specialists. METHODS: This retrospective pre–post study included adult inpatients treated with intravenous antimicrobials between April 2016 and March 2020. Outcome (eg, length of hospital stay [LOS], drug cost) and process measures (eg, type of intervention, length of therapy) were compared between 2 time periods: pre-ASP (April 2016–March 2018) and post-ASP (April 2018–March 2020). RESULTS: We included 5419 and 5634 patients in the pre- and post-ASP periods, respectively. The most common types of interventions were adjusting length of therapy (49.5%), additional laboratory tests (27.1%), antimicrobial change (16.2%), and dosage of antimicrobial (7.1%). After ASP implementation, LOS significantly decreased (14.8 vs 13.8 days, P < .01), along with the length of therapy, empirical use of antipseudomonal and anti–methicillin-resistant Staphylococcus aureus drugs, and number of days to de-escalation. No significant differences were noted in 30-day mortality, 30-day readmission, or de-escalation rates. On average, the antimicrobial cost per hospitalization decreased from US$173.03 to US$120.66. CONCLUSIONS: Pharmacist-led ASP interventions that focus on the length of therapy have the potential to reduce LOS in hospitals without ID specialists. Overall, this study showed that ASPs can be effectively implemented in medium-sized hospitals without ID specialists.