Introduction:We aimed to assess antibiotic stewardship by quantifying the use offirst-dose intravenous(IV) vs oral-only antibiotics and the frequency with which antibiotic class was changed for dischargedpatients. Secondary aims included the following: evaluation of the relative length of stay (LOS);differences in prescribing patterns between clinician types; differences between academic andcommunity settings; assessment of prescribing patterns among emergency department (ED) diagnoses;and frequency of return visits for patients in each group.Methods:This was a retrospective cohort study including patients presenting to EDs with infections whowere discharged from our Midwest healthcare system consisting of 17 community hospitals and oneacademic center. We included infection type, antibiotic class and route of administration, type ofinfection, LOS, return visit within two weeks, clinician type, and demographics. Data were collectedbetween June 1, 2018-December 31, 2021 and analyzed using descriptive statistics.Results:We had 77,204 ED visits for patients with infections during the study period, of whom 3,812received IV antibiotics during their visit. There were more women (62.4%) than men included. Of the3,812 patients who received IV antibiotics, 1,026 (34.3%) were discharged on a different class ofantibiotics than they received. The most common changes were from IV cephalosporin to oral quinoloneor penicillin. Patients treated with IV antibiotics prior to discharge had a longer LOS in the ED (mediandifference of 102 minutes longer for those who received IV antibiotics). There was not a significantdifference in the use of IV antibiotics between the academic center and community sites included inthe study.Conclusion:Administering IV antibiotics as afirst dose prior to oral prescriptions upon discharge iscommon, as is shifting classes from the IV dose to the oral prescription. This offers an opportunity forintervention to improve antibiotic stewardship for ED patients as well as reduce cost and length of stay