Evaluation of an Antimicrobial Time-Out on Antimicrobial Utilization at a Large Health System

Background:
Infectious Diseases Society of America and Society for Healthcare Epidemiology Guidelines for Implementing an Antibiotic Stewardship Program (ASP) and the CDC Core Elements of Hospital ASP include antimicrobial time-outs (ATO) as an example of a recommended action.  There are limited data evaluating the impact of ATOs on antimicrobial use.  Cleveland Clinic Health-System (CCHS) implemented a 72 hour ATO for antimicrobials with an empiric indication and no stop date within the electronic health record. This study aimed to assess the effect of an ATO on antimicrobial utilization. 

Methods:
Retrospective, quasi-experimental study of patients between October 1-December 31, 2016 and 2017 who received at least one systemic antimicrobial agent while admitted to a US-based CCHS hospital.  Primary objective was to compare the Days of Therapy (DOT) per 1000 patient days of broad spectrum agents before and after ATO implementation. Secondary objectives included comparing indications for use, actions taken as a result of the ATO, and rate of Clostridium difficile.  Antimicrobial groupings per National Healthcare Safety Network AUR Module.

Results:
In 4Q2016, there were 75,982 antimicrobial orders in 31,945 encounters, of which 5029 encounters had an empiric antimicrobial active at 72 hrs.  In 4Q2017, there were 78,418 antimicrobial orders in 33,378 encounters, which led to 38,129 ATOs in 6138 encounters.  Mean duration of therapy was 71 hrs in 4Q2016 vs. 62 hrs in 4Q2017, p<0.05 (Fig 1).  DOT/1000 patient days did not differ (Fig 2).  Orders with the indication of pathogen directed did not change (14.1% vs. 14.4%; p=0.11).  Of 16,009 ATOs acknowledged by clinicians, 2195 (14%) prompted antimicrobial discontinuation, while 684 alerts (4%) prompted de-escalation.  There was no difference in encounters with positive C. difficile PCR, 123 (2.4%) vs. 152 (2.5%).

Conclusion:
Implementation of an ATO for all antimicrobials within an electronic health record decreased duration of therapy but not DOT/1000 patient days.  Further study is needed to define optimal ATO characteristics (targeted vs. all antimicrobials, 48 vs. 72 hrs, etc) and potential impact on utilization and appropriate antimicrobial usage.

Fig 1.

Fig 2.