Guideline impact on antibiotic use for tooth extraction across facility types in Japan: an interrupted time series analysis using a health insurance claims database

Objective: The objective of this study was to evaluate the impact of dental antibiotic guidelines recommending amoxicillin (AMPC) over third-generation cephalosporins (3GCs) for prophylactic use on surgical site infections (SSIs), prescription patterns, and cost-effectiveness across facility types, considering the presence of infection control departments and ward pharmacists. Method: Using a health insurance claims database of individuals aged ≤ 75 years, we performed an interrupted time-series analysis of dental visits with tooth extractions from April 2012 to March 2024. A segmented regression model was applied to assess the impact of antibiotic guidelines (December 2014, 2014 guidelines; April 2016, 2016 guidelines) on 3GCs days of therapy (DOT) and SSI rates. Antibiotic costs and in-hospital vs out-of-hospital prescription patterns in dental clinics were also evaluated. Results: Overall, the number of 3GCs DOT decreased, although the impact of the guidelines differed between facilities. After the implementation of the 2014 guidelines, 3GCs use decreased in hospitals, but not in dental clinics. After the implementation of the 2016 guidelines, it was further reduced in hospitals with infection control departments and ward pharmacists, and a decline in 3GCs use in dental clinics was initiated. No changes were observed in hospitals with infection control departments alone. The shift from 3GCs to AMPC was more evident in out-of-hospital prescriptions than in in-hospital prescriptions. SSI rates remained unchanged; however, antibiotic costs decreased significantly over time. Conclusion: Guideline-based antimicrobial stewardship can reduce 3GC use and healthcare costs without compromising patient safety. Our findings highlight the importance of a multi-disciplinary collaboration to enhance the impact of guidelines.