Time-series analysis of antimicrobial use and resistance trends in a tertiary hospital in China from 2017 to 2022: Implications for national stewardship efforts.

OBJECTIVES

To evaluate five-year trends (2017-2022) in antimicrobial consumption and antimicrobial resistance in a tertiary hospital in China, and to assess the association between antimicrobial use and resistance using time-series modelling.

METHODS

This retrospective study analysed in-patient hospital antimicrobial consumption using defined daily doses (DDD) and antimicrobial use density (AUD; DDD per 100 patient-days). Temporal trends were evaluated using linear regression, and the association between antimicrobial use and antimicrobial resistance were evaluated using autoregressive integrated moving average (ARIMA) models.

RESULTS

Antimicrobial consumption declined markedly (AUD of 65.51 in 2017 to 40.42 in 2021). Significant reductions were observed in intensive care and major surgical departments. Second- and third-generation cephalosporins were the most commonly used agents while aminoglycosides and imidazole derivatives demonstrated statistically significant downward trends (p < 0.05). Escherichia coli and Klebsiella pneumoniae were consistently among the most commonly isolated organisms. Significant reductions in resistance were observed for Acinetobacter baumannii to tigecycline (32.46%-3.33%, p < 0.001) and imipenem; (71.34% to 21.05%, p = 0.008, and for Pseudomonas aeruginosa to imipenem (54.19% to 16.67%, p = 0.004). In contrast, fluoroquinolones resistance in E. coli increased significantly (46.90% to 74.61%, p = 0.024). ARIMA modelling showed significant positive associations between carbapenem use and imipenem resistance for A. baumannii (p = 0.013), and between fluoroquinolone use and levofloxacin resistance for the same organism (p = 0.001).

CONCLUSIONS

Antimicrobial use declined and resistance improved for several clinically-important Gram-negative pathogens. Rising fluoroquinolone resistance for E. coli highlights the need for ongoing coordinated and targeted antimicrobial stewardship.