Cefuroxime compared to piperacillin/tazobactam as empirical treatment of Escherichia coli bacteremia in a low Extended-spectrum beta-lactamase (ESBL) prevalence cohort Sara Thønnings,1,2 Filip Jansåker,1,3 Kim Oren Gradel,4,5 Bjarne Styrishave,2 Jenny Dahl Knudsen11Department of Clinical Microbiology, Copenhagen University Hospital, Hvidovre, Denmark; 2Toxicology Laboratory, Analytical BioSciences, Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark; 3Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; 4Center for Clinical Epidemiology, Odense University Hospital, Odense, Denmark; 5Research Unit of Clinical Epidemiology, Institute of Clinical Research, University of Southern Denmark, Odense, DenmarkObjectives: On January 18, 2010, a part of the capital region of Denmark shifted the empirical treatment of febrile conditions from cefuroxime to piperacillin/tazobactam. We compare empirical treatment with piperacillin/tazobactam versus cefuroxime for Escherichia coli bacteremia with regard to 14 days mortality, in a low prevalence cohort of Extended-spectrum beta-lactamase-producing E. coli.Methods: From January 18, 2010 to December 31, 2012, we conducted a retrospective cohort study including patients with E. coli bacteremia from six university hospitals in Copenhagen, Denmark. Clinical and laboratory information was obtained from a bacteremia research database, including information on comorbidity, and we used Cox proportional hazard analysis to asses all-cause 14 days mortality.Results: A total of 568 patients receiving either cefuroxime