Long-term National Trends in Pediatric Oral Antibiotic Prescriptions in Japan, 2011-2022.

Introduction: Antimicrobial resistance is a major global health challenge, prompting Japan to implement a National Action Plan in 2016. This study examined long-term national trends from 2011 to 2022 to evaluate the impact of national health policy and identify priority areas for future antimicrobial stewardship efforts. Methods: We conducted time-series analyses of oral antibiotic prescriptions among children aged 0-19 years in Japan using 408 million outpatient claims from the National Database between fiscal years 2011 and 2022. Antibiotic use was measured as days of therapy per 1,000 pediatric inhabitants per day (DOTs/PID). Trends and relative changes were evaluated using multivariable Poisson regression, with additional analyses stratified by age and prefecture. Results: Total antibiotic prescriptions decreased by 58.6% between 2011 and 2022 (from 33.4 to 13.8 DOTs/PID), with a marked slope change (-8.2%) following the implementation of the National Action Plan in 2016 and a substantial level drop (-36.4%) during the coronavirus disease 2019 pandemic. We also observed marked reductions in macrolides and cephalosporins but a 23.9% increase in tetracyclines. Reductions were limited among adolescents aged 15-19 years, and tetracycline use increased particularly after 2017. All prefectures showed declines in antibiotic use (38%-67%), although quinolone prescriptions varied widely, and tetracycline use increased in most prefectures. Conclusion: Pediatric antibiotic prescriptions in Japan decreased substantially between 2011 and 2022, particularly for macrolides and cephalosporins, while tetracycline use increased among adolescents. These long-term national trends provide important implications for the need for sustained, age-specific interventions in the post-pandemic era.