Limitations of the AWaRe antibiotic classification during the 2024 Mycoplasma pneumoniae epidemic in Tokyo

The utility of AWaRe antibiotic classification for evaluating antimicrobial stewardship in clinics during epidemics of specific, infectious diseases remains unknown. This study aimed to examine antibiotic prescribing patterns using the AWaRe classification during a Mycoplasma pneumoniae epidemic in Tokyo.

Oral antibiotic prescription data from January 2024 to June 2025 were obtained from the prescription surveillance system of 11 clinics in the Tama regional network (Tama cohort), a subset of all registered clinics in Tokyo (Tokyo cohort). For analysis, the pre-epidemic period, epidemic period, and post-epidemic period were defined as January-June 2024, July-December 2024, and January-June 2025, respectively. The primary outcome was the change in Access antibiotic proportions across the three periods. The secondary outcome was the difference in this change between cohorts.

In total, 8,420 and 526,822 antibiotic prescriptions were issued by the Tama cohort and the Tokyo cohort, respectively. In the Tama cohort, Access antibiotic proportions were 64 %, 48 %, and 75 % during the pre-epidemic, epidemic, and post-epidemic periods, respectively; the corresponding values in the Tokyo cohort were 37 %, 32 %, and 40 %. Compared with the Tokyo cohort, estimated changes in Access proportions in the Tama cohort were -11.7 % (95 % CI: -14.2 to -9.2) from pre-epidemic to epidemic period, and +19.0 % (95 % CI: 16.6 to 21.5) from epidemic to post-epidemic period.

Access proportions temporarily decreased during the 2024 M. pneumoniae epidemic, particularly in the Tama cohort, where the baseline Access proportion was high, indicating potential limitation of AWaRe indicators under epidemic conditions.