Investigating the WHO's AWaRe classification for assessing antimicrobial stewardship programs: A single-center study.

BACKGROUND: AWaRe (Access, Watch, Reserve) classification proposed by the World Health Organization (WHO) holds potential for assessing antimicrobial stewardship programs (ASPs). However, increase in antibiotics for non-infectious treatment might undermine the effectiveness of using the AWaRe classification for assessing ASPs. The study aimed to evaluate the antimicrobial usage by AWaRe classification and specify issues for assessing ASPs.

METHODS: The retrospective study was conducted in a single center within an 845-bed hospital. Antimicrobial usage data for outpatients were obtained from medical records used for billing purposes. Antimicrobials for non-infectious treatment were defined by smaller dose of macrolides, tetracyclines with pemphigoid, rifaximin, and prophylactic sulfamethoxazole-trimethoprim (ST) agent.

RESULTS: The usage of antimicrobials for non-infectious treatment increased from 25.3 % to 50.1 % for the ratio of the amount to defined daily doses (DDDs) and from 46.3 % to 65.9 % for prescription days between January 2015 and March 2024. The usage of prophylactic sulfamethoxazole-trimethoprim (ST) agents increased by 2.4 times, and the usage of rifaximin increased by more than 100 times. Macrolides for non-infectious treatment was stable or fluctuated while that for infection treatment decreased to that amount for non-infectious treatment. The ratios for Access increased from 31.9 % to 58 % and 42 % to 78 % by excluding the antimicrobials for non-infectious treatment.

CONCLUSIONS: The findings suggested that the AWaRe classification might not be appropriate for assessing ASPs and comparing them among hospitals.