Vol.74 No.2 March 2026
Evaluation of the impact of pharmacist-driven antimicrobial stewardship on the management of Staphylococcus aureus bacteremia in an acute care hospital: An exploratory single-center study before and after the introduction of case-based learning by an infectious disease specialist
1)Department of Pharmacy, Toda Chuo General Hospital, 1-19-3 Honcho Toda-city, Saitama, Japan
2)Faculty of Pharmaceutical Sciences, Teikyo Heisei University
3)Department of Infection Prevention and Control, Tokyo Medical University Hospital
Abstract
Staphylococcus aureus bacteremia (SAB) is a life-threatening infection with a high mortality rate, and strict adherence to appropriate care bundles is essential. Pharmacist involvement in antimicrobial stewardship programs (ASPs) has been shown to be effective; however, in Japan, the educational infrastructure and staff placements for infectious disease (ID) specialists remain insufficient. Toda Chuo General Hospital is an acute care facility with no full-time ID specialist. In April 2022, the hospital launched a weekly Case-Based Learning (CBL) program led by a part-time ID specialist. This initiative prompted a revision of the pharmacist-driven SAB management strategy, with a focus on clarifying antimicrobial selection and reinforcing diagnostic approaches. This retrospective study evaluated the impact of pharmacist-driven ASP activities on SAB management and the activity of a dedicated antimicrobial stewardship team (AST) pharmacist before and after CBL implementation in an acute care hospital.
Adult patients with SAB admitted between April 2020 and March 2024 were divided into two groups: before introduction of the CBL program (pre-CBL) and after introduction of the CBL program (post-CBL). Process measures, including the overall adherence rate to care bundle components, and outcome measures, such as the 30-day mortality, were assessed. The effect of the CBL program on the AST pharmacist activities was examined by comparing cases with and without concordance on the presumed source of infection between the attending physician and the AST pharmacist, and analyzing associated factors.
The overall care bundle adherence rate for SAB improved significantly after introduction of the CBL program (39.2% vs. 60.8 %, p<0.01), while no significant difference was observed in the 30-day mortality between before and after introduction of the CBL program (5/34 [14.7%] vs. 8/34 [23.5%], p=0.54). In the post-CBL group, the presumed infection source differed between the attending physician and the AST pharmacist in 9 cases; however, in all of these cases the AST pharmacist's assessment was consistent with that of the ID specialist, and in 2 cases, the AST pharmacist's input was instrumental in establishing the diagnosis of suppurative thrombophlebitis as the infection source.
Implementation of the CBL program led by a part-time ID specialist was associated with a significant increase in the adherence to SAB care bundles in pharmacist-driven ASPs. These findings highlight the necessity for continuous re-evaluation of ASPs and suggest the potential value of CBL programs for enhancing the competence of pharmacists involved in ID care.
Key word
antimicrobial stewardship, Staphylococcus aureus bacteremia, pharmacist, human resource, full-time equivalent
Received
July 7, 2025
Accepted
November 21, 2025
Jpn. J. Chemother. 74 (2): 153-162, 2026
