Design of a panel of indicators for antibiotic stewardship programs in the Emergency Department

Impact of an antibiotic stewardship programme in the emergency department of a secondary hospital

INTRODUCTION

Emergency Departments (ED) are usually the first point of contact between patients and hospitals. There is no solid evidence evaluating the activity of antibiotic stewardship programs (ASP) in EDs. We aimed to assess antibiotic prescription appropriateness after the implementation of an ASP in an ED in May 2019 and to determine the risk factors associated with inappropriate antibiotic prescription.

METHODS

A cross-sectional study was conducted with patients admitted to the ED of the University Hospital Fundación Alcorcón, a second-level university hospital in Spain. All patients admitted to the ED in May 2019, March 2021, and between October and November 2022 were included. We analyzed demographic data, epidemiological variables, comorbidities, empirical antibiotic treatment, previous isolations, and treatment duration. A 30-day follow-up was implemented.

RESULTS

A total of 402 patients were included. No significant improvement in antibiotic appropriateness was observed between the first and second periods (50 % vs. 57.3 %; OR = 1.3, 95 % CI: 0.65-2.76, p = 0.424), while antibiotic appropriateness increased between the first and third periods (50 % vs. 71.2 %; OR = 2.47, 95 % CI: 1.28-4.79, p = 0.007). Factors associated with antibiotic inadequacy were having a urinary catheter (33 % vs. 56 %, p = 0.008, OR: 2.62, 95 % CI: 1.29-5.33), a history of infection/colonization by multidrug-resistant microorganisms (32 % vs. 57 %, p = 0.007), and coming from a retirement home or medium-stay hospital (32 % vs. 47 % vs. 53 %, p = 0.015).The overall use of carbapenems was 9 % (n = 36), showing a decrease in consumption between the first and third periods (26.2 % vs. 7 % vs. 7 %, p < 0.01).

Antimicrobial Stewardship in the Emergency Department Observation Unit: Definition of a New Indicator and Evaluation of Antimicrobial Use and Clinical Outcomes

We aimed to define a novel indicator for monitoring antimicrobial use specifically in the Emergency Department Observation Unit (EDOU) and to assess the long-term impact of an institutional education-based antimicrobial stewardship program (ASP) on the antimicrobial prescribing pattern and clinical outcomes in this setting. A quasi-experimental interrupted time-series study was performed from 2011 to 2022. An educational ASP was implemented at the EDOU in 2015. To estimate changes in antimicrobial use, we designed an indicator adjusted for patients at risk of antimicrobial prescribing: defined daily doses (DDDs) per 100 patients transferred from the Emergency Department to the Observation Unit (TOs) per quarter. The number of bloodstream infections (BSIs) and the crude all-cause 14-day mortality were assessed as clinical outcomes. Antimicrobial use showed a sustained reduction with a trend change of -1.17 DDD per 100 TO and a relative effect of -45.6% (CI95% -64.5 to -26.7), particularly relevant for meropenem and piperacillin-tazobactam, with relative effects of -80.4% (-115.0 to -45.7) and -67.9% (-93.9 to -41.9), respectively. The incidence density of all BSIs increased significantly during the ASP period, with a relative effect of 123.2% (41.3 to 284.7). The mortality rate remained low and stable throughout the study period, with an absolute effect of -0.7% (-16.0 to 14.7). The regular monitoring of antimicrobial use in the EDOU by using this new quantitative indicator was useful to demonstrate that an institutional education-based ASP successfully achieved a long-term reduction in overall antimicrobial use, with a low and steady BSI mortality rate.