Impact of an antimicrobial stewardship programme to optimize antimicrobial use for outpatients at an emergency department

Background: Antimicrobial stewardship programmes (ASPs) have been effective in optimizing antibiotic use for inpatients. However, an emergency department's fast-paced clinical setting can be challenging for a successful ASP. Aim: In April 2015, an ASP was implemented in our emergency department and we aimed to determine its impact on antimicrobial use for outpatients. Methods: This was a single-centre study comparing the quality of antibiotic prescriptions between a one-year period before ASP implementation (November 2012 to October 2013) and a one-year period after its implementation (June 2015 to May 2016). For each period, antimicrobial prescriptions for all adult outpatients (hospitalized for <24 h) were evaluated by an infectious disease specialist and an emergency department physician to assess compliance with local prescribing guidelines. Inappropriate prescriptions were then classified. Findings: Before and after ASP, 34,671 and 35,925 consultations were registered at our emergency department, of which 25,470 and 26,208 were outpatients. Antimicrobials were prescribed in 769 (3.0%) and 580 (2.2%) consultations, respectively (P < 0.0001). There were 484 (62.9%) and 271 (46.7%) (P < 0.0001) instances of non-compliance with guidelines before and after ASP implementation. Non-compliance included unnecessary antimicrobial prescriptions, 197 (25.6%) vs 101 (17.4%) (P < 0.0005); inappropriate spectrum, 108 (14.0%) vs 54 (9.3%) (P = 0.008); excessive treatment duration, 87 (11.3%) vs 53 (9.1%) (P > 0.05); and inappropriate choices, 11 (1.4%) vs 15 (2.6%) (P > 0.05). Conclusion: The implementation of an ASP markedly decreased the number of unnecessary antimicrobial prescriptions, but had little impact on most other aspects of inappropriate prescribing. (C) 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.