ABSTRACT
PURPOSE: To provide an overview of the impact of pharmacist interventions on antibiotic prescribing and the resultant clinical outcomes in an outpatient antibiotic stewardship program (ASP) in the United States. METHODS: Reports on studies of pharmacist-led ASP interventions implemented in US outpatient settings published from January 2000 to November 2020 and indexed in PubMed or Google Scholar were included. Additionally, studies documented at the ClinicalTrials.gov website were evaluated. Study selection was based on predetermined inclusion criteria; only randomized controlled trials, observational studies, nonrandomized controlled trials, and case-control studies conducted in outpatient settings in the United States were included. The primary outcome was the observed differences in antibiotic prescribing or clinical benefits between pharmacist-led ASP interventions and usual care. RESULTS: Of the 196 studies retrieved for full-text review, a cumulative total of 15 studies were included for final evaluation. Upon analysis, we observed that there was no consistent methodology in the implementation of ASPs and, in most cases, the outcome of interest varied. Nonetheless, there was a trend toward improvement in antibiotic prescribing with pharmacist interventions in ASPs compared with that under usual care (P < 0.05). However, the results of these studies are not easily generalizable. CONCLUSION: Our findings suggest a need for a consistent approach for the practical application of outpatient pharmacist-led ASPs. Managed care organizations could play a significant role in ensuring the successful implementation of pharmacist-led ASPs in outpatient settings.