Efficacy of a postprescription review of broad-spectrum antimicrobial agents with feedback: A 4-year experience of antimicrobial stewardship at a tertiary care center

Background. An inpatient antimicrobial stewardship program is vital for judicious antimicrobial use. We began a hospital-wide, postprescription review with feedback (PPRF) in 2014; the present study evaluated its impact on antimicrobial consumption and clinical outcomes over 4 years. Methods. Once-weekly PPRF for carbapenems and piperacillin/tazobactam was implemented. We tracked the data on each antimicrobial use as days of therapy (DOT) per 1000 patient-days (PD). Changes in the incidence of drug-resistant organisms, in-hospital mortality, and length of hospital stay per month were analyzed by an interrupted time series. Results. Carbapenem use continued to decline in the preintervention and intervention periods (−0.73 and −0.003 DOT/1000 PD, respectively), and although monthly average use remained low in the intervention period (8.3 DOT/1000 PD), more importantly, the postintervention change in the slope diminished significantly. Piperacillin/tazobactam use showed a steeper decline in the intervention period, but the change in the slope was not statistically significant (change in slope: −0.20 DOT/1000 PD per month [P = .16]). Postintervention use of narrower-spectrum antimicrobials including ampicillin/sulbactam (change in slope: +0.58 DOT/1000 PD per month [P < .001]) increased. The antimicrobial cost and the monthly average length of hospital stay also declined (−37.4 USD/1000 PD per month [P < .001] and −0.04 days per month [P < .001], respectively), whereas few postintervention changes in the incidence of drug-resistant organisms were observed. Conclusions. In our study, the 4-year PPRF for broad-spectrum antimicrobials coincided with a reduction in the use of targeted antimicrobials and resulted in an improvement in 1 patient-centered outcome, thus conferring the additional benefit of reducing expenditures for antimicrobials.