[Impact of the Antimicrobial Stewardship Team Intervention Focusing on Changes in Prescribing Trends and the Rate of Carbapenem-resistant P. aeruginosa].

Antimicrobial stewardship (AS) intervention strategy is a critical process in promoting appropriate antibiotic use, thus preventing unnecessarily prolonged therapy and reducing antimicrobial resistance (AMR). Although limiting unnecessary carbapenem use by AS intervention is speculated to reduce AMR, there is a lack of specific data on the efficacy of AS team (AST) intervention regarding carbapenem-resistant Pseudomonas aeruginosa (CRPA). Consequently, this study aimed to evaluate the impact of our AS strategy on carbapenem use and CRPA. The AS intervention strategy was launched in July 2017 and consisted of daily audits and feedback on carbapenem use. We evaluated the 4-year prescription trend, including the rate of switching to other antimicrobials, and the rate of CRPA and the days of therapy required prior to and after the beginning of the AST intervention. The rate of switching to narrow-spectrum antibiotics and the discontinuation of carbapenem treatment were significantly higher in the pre-intervention period compared with the post-intervention period. (7.0% vs. 14.5%; p<0.001; 54.1% vs. 50.9%; p=0.027). However, there were no significant differences in the rate of CRPA prior to and after the beginning of the AST intervention. Furthermore, there was no correlation found between consumption and resistance rate (Pearson's r=0.123). Our results suggest that it is extremely important for AST to promote de-escalation and reduce unnecessary use, while the combination of process and outcome indicators other than antimicrobial consumption and resistance rate are required for the evaluation of the AS programs.