S2. Antimicrobial Stewardship outcomes assessment (clinical and economic)
Oral Abstract Submission
Hospital-based antimicrobial stewardship interventions and metrics have typically focused only on inpatient antimicrobial exposure. However, single-center studies have found a large portion of antimicrobial exposure occurs immediately after hospital discharge. We sought to describe antimicrobial-prescribing upon hospital discharge across the Veterans Health Administration (VHA) and to compare inpatient and post-discharge antimicrobial use at the hospital-level.
This retrospective study used national VHA administrative data to identify all acute-care admissions from January 1, 2014 -December 31, 2016. Post-discharge antimicrobials were defined as oral outpatient antimicrobials prescribed at the time of hospital discharge. We measured inpatient days of therapy (DOT) and post-discharge DOTs. At the hospital-level, inpatient DOTs per 100 admissions were compared with post-discharge DOTs per 100 admissions using Spearman’s rank-order correlation.
Results : Among 1.7 million acute-care admissions across 122 VHA hospitals, 46.1% were administered inpatient antimicrobials, and 19.9% were prescribed an oral antimicrobial at discharge. Fluoroquinolones were the most common antimicrobial prescribed at discharge among 335,396 antimicrobial prescriptions (38.3%). At the hospital-level, median inpatient antimicrobial use was 331.3 DOTs per 100 admissions (interquartile range (IQR) 284.9-367.9) and median post-discharge use was 209.5 DOTs per 100 admissions (IQR 181.5-239.6). Thirty-nine percent of the total duration of antimicrobial exposure occurred after hospital discharge. The metrics of inpatient DOTs per 100 admissions and post-discharge DOTs per 100 admissions were weakly correlated at the hospital-level (rho=0.44, p<0.0001).
Conclusion : Antimicrobial-prescribing at hospital discharge was common and contributed substantially to the total antimicrobial exposure associated with an acute-care hospital stay. A hospital’s inpatient antimicrobial use was only weakly correlated with its post-discharge antimicrobial use. Antimicrobial stewardship interventions should specifically target antimicrobial-prescribing at discharge.