Association between National Antimicrobial Stewardship Policies and Antibiotic Selection for Uncomplicated Cystitis in Japan: A 10-Year Database Study

This study investigated the association between Japan's antimicrobial stewardship policies and antibiotic selection for uncomplicated cystitis from 2013 to 2022, using a large-scale claims database. We analyzed approximately 520,000 female outpatients aged 15-64 years. Antibiotic use was quantified using defined daily dose and categorized according to the World Health Organization's AWaRe classification. An interrupted time-series analysis assessed changes in prescribing trends following policy implementation. Throughout the study period, "Watch" group antibiotics, primarily fluoroquinolones and third-generation cephalosporins, remained the most frequently prescribed agents. However, the proportion of recommended "Access" group antibiotics significantly increased from 4.5% in 2013 to 10.6% in 2022. The interrupted time-series analysis demonstrated a significant acceleration in the upward trend of Access group antibiotic use following the 2016 National Action Plan on Antimicrobial Resistance (p<0.001), with a further increase observed after the 2018 revision of the remuneration system to promote antimicrobial stewardship teams (p<0.01). The proportion of facilities classified as "poor," defined by an Access group prescription rate of less than 30%, decreased from 97.4% in the first period (January 2013-March 2017) to 90.2% in the final period (April 2019-December 2022), suggesting a temporal shift toward higher Access group use. In conclusion, although positive changes in prescribing behavior have been observed since the implementation of national policies, reliance on Watch group antibiotics persists, and Japan remains far from WHO's 60% Access target. Achieving this will require comprehensive strategies beyond current policies, including aligning guidelines with the AWaRe framework and addressing limited treatment options for clinicians.