Volume control but structural imbalance: AWaRe-based assessment of antimicrobial stewardship in Shanghai, China...

Recognizing irrational use as the key driver of antimicrobial resistance (AMR), the World Health Organization (WHO) introduced the AWaRe (Access, Watch, Reserve) classification to enhance prescribing structures. This study aims to comprehensively elucidate the long-term trends and structural evolution of antimicrobial use, providing evidence to inform the transition from volume-based control to structure-oriented optimization.

The Anatomical Therapeutic Chemical/Defined Daily Dose (ATC/DDD) method and AWaRe classification were applied to assess the overall antimicrobial use and structural rationality across institutions, and further analyzed concentration indices to reveal clinical dependence on a limited set of agents.

From 2016 to 2024, the overall antimicrobial usage and expenditure decreased by 57.94% and 22.07% with strong concordance. However, the prescribing structure severely deviated from the WHO's target of ≥ 60.00% Access category. The proportion of Access category remained below 20.00%, while Watch category predominated but declined gradually, and Reserve category remained below 1.00% until a slight rebound after 2023, especially in secondary and tertiary hospitals. The annual top 10 agents consistently accounted for over 50.00%, exhibiting an initial decline in concentration followed by a slight rebound after 2021. In 2016, cefuroxime sodium injection constituted 63.50%, Herfindahl-Hirschman Index (HHI) was 0.41, later becoming more dispersed. Levofloxacin tablets have ranked first in utilization and remained high since 2022, contributing to a rebound in concentration (HHI = 0.06).

Antimicrobial stewardship (AMS) in Shanghai, China has achieved success in controlling volume, but still faces structural challenges. Insufficient Access, prolonged dominance of broad-spectrum Watch, and Reserve slightly rebound suggest potential AMR escalation. It is recommended to implement tiered, structure-oriented strategies and integrate pathogen surveillance with clinical data to assess prescriptions and guide targeted AMR control.