Impact of an Antimicrobial Utilization Program on Antimicrobial Use at a Large Teaching Hospital: A Randomized Controlled Trial

BACKGROUND. Multidisciplinary antimicrobial utilization teams (AUTs) have been proposed as a mechanism for improving antimicrobial use, but data on their efficacy remain limited. OBJECTIVE. To determine the impact of an AUT on antimicrobial use at a teaching hospital. DESIGN. Randomized controlled intervention trial. SETTING. A 953-bed, public, university-affiliated, urban teaching hospital. PATIENTS. Patients who were given selected antimicrobial agents (piperacillin-tazobactam, levofloxacin, or vancomycin) by internal medicine ward teams. INTERVENTION. Twelve internal medicine teams were randomly assigned monthly: 6 teams to an intervention group (academic detailing by the AUT) and 6 teams to a control group that was given indication-based guidelines for prescription of broad-spectrum antimicrobials (standard of care), during a 10-month study period. MEASUREMENTS. Proportion of appropriate empirical, definitive (therapeutic), and end (overall) antimicrobial usage. RESULTS. A total of 784 new prescriptions of piperacillin-tazobactam, levofloxacin, and vancomycin were reviewed. The proportion of antimicrobial prescriptions written by the intervention teams that was considered to be appropriate was significantly higher than the proportion of antimicrobial prescriptions written by the control teams that was considered to be appropriate: 82% versus 73% for empirical (risk ratio [RR], 1.14; 95% confidence interval [CI], 1.04-1.24), 82% versus 43% for definitive (RR, 1.89; 95% CI, 1.53-2.33), and 94% versus 70% for end antimicrobial usage (RR, 1.34; 95% CI, 1.25-1.43). In multivariate analysis, teams that received feedback from the AUT alone (adjusted RR, 1.37; 95% CI, 1.27-1.48) or from both the AUT and the infectious diseases consultation service (adjusted RR, 2.28; 95% CI, 1.64-3.19) were significantly more likely to prescribe end antimicrobial usage appropriately, compared with control teams. CONCLUSIONS. A multidisciplinary AUT that provides feedback to prescribing physicians was an effective method in improving antimicrobial use.