408. Benchmarking the Use of New β-lactams Utilizing a Novel Metric of Microbiological Burden

Abstract Background Several methods are used to account for various hospital characteristics when comparing antimicrobial use (AU) between heterogenous hospitals. Recently, a new stewardship metric that adjusts AU by microbiological burden (a-AU) of the bacteria was proposed (Figure 1). It accounts resistant phenotypes observed at given institution, allowing more balanced comparison across This multicenter retrospective cohort study examined β-lactams Gram-negative (GNB) with difficult-to-treat resistance (DTR) both and adjusted metrics in southeastern United States. Methods determined 9 hospitals within Southeastern Research Group Endeavor (SERGE-45) 2015 2020. New included ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilastatin/relebactam, cefiderocol. prevalence GNB DTR including Enterobacterales, Pseudomonas aeruginosa, Acinetobacter species. defined as nonsusceptibility all following: cefepime or ceftazidime, levofloxacin ciprofloxacin, meropenem imipenem, piperacillin/tazobactam if tested. Hospitals were ranked a-AU from lowest highest. Descriptive statistics utilized. Results The cumulative mean 2020 1.96 (range 0.10 6.44) 2.3 0.20 8.05) days therapy (DOT)/1000 patient days, respectively 2). After adjusting DTR, 6 moved least 1 position ranking (2 up; 4 down) 2 positions ranking. Conclusion Overall, increased after local suggests potential higher antibiotics relationship DTR. More than half had shift adjustment reflecting antibiotic Disclosures P. Brandon Bookstaver, PharmD, Spero Therapeutics: Advisor/Consultant Julie Ann Justo, MS, FIDSA, BCPS-AQ ID, bioMerieux: Honoraria|bioMerieux: Honoraria|Entasis Advisor/Consultant|Entasis Advisor/Consultant|Gilead Sciences: Advisor/Consultant|Merck & Co: Advisor/Consultant|Shionogi: Advisor/Consultant|Shionogi Inc.: Advisor/Consultant|Spero Honoraria|Spero Honoraria|Vaxart: Stocks/Bonds Bruce M. Jones, Pharm.D., BCPS, AbbVie: Advisor/Consultant|AbbVie: Honoraria|La Jolla: Honoraria|Melinta: Advisor/Consultant|Paratek: Honoraria|Regeneron: Honoraria.