title: Comparative Effectiveness of Cefazolin Versus Nafcillin or Oxacillin for Treatment of Methicillin-Susceptible Staphylococcus aureus Infections Complicated by Bacteremia: A Nationwide Cohort Study.
abstract: To treat patients with methicillin-susceptible Staphylococcus aureus (MSSA) infections, β-lactams are recommended for definitive therapy; however, the comparative effectiveness of individual β-lactams is unknown. This study compared definitive therapy with cefazolin vs nafcillin or oxacillin among patients with MSSA infections complicated by bacteremia.
  
  
  
  This retrospective study included patients admitted to 119 Veterans Affairs hospitals from 2003 to 2010. Patients were included if they had a blood culture positive for MSSA and received definitive therapy with cefazolin, nafcillin, or oxacillin. Cox proportional hazards regression and ordinal logistic regression were used to identify associations between antibiotic therapy and mortality or recurrence. A recurrent infection was defined as a MSSA blood culture between 45 and 365 days after the first MSSA blood culture.
  
  
  
  Of 3167 patients, 1163 (37%) patients received definitive therapy with cefazolin. Patients who received cefazolin had a 37% reduction in 30-day mortality (hazard ratio [HR], 0.63; 95% confidence interval [CI], .51-.78) and a 23% reduction in 90-day mortality (HR, 0.77; 95% CI, .66-.90) compared with patients receiving nafcillin or oxacillin, after controlling for other factors. The odds of recurrence (odds ratio, 1.13; 95% CI, .94-1.36) were similar among patients who received cefazolin compared with patients who received nafcillin or oxacillin, after controlling for other factors.
  
  
  
  In this large, multicenter study, patients who received cefazolin had a lower risk of mortality and similar odds of recurrent infections compared with nafcillin or oxacillin for MSSA infections complicated by bacteremia. Physicians might consider definitive therapy with cefazolin for these infections.
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.|Department of Epidemiology, College of Public Health, University of Iowa.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: McDanel
authors.affiliation: Department of Epidemiology and Public Health, University of Maryland School of Medicine.|Veterans Affairs Maryland Health Care System, Baltimore.
authors.forename: Mary-Claire
authors.initials: MC
authors.lastname: Roghmann
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.|Department of Epidemiology, College of Public Health, University of Iowa.
authors.forename: Eli N
authors.initials: EN
authors.lastname: Perencevich
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ohl
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Goto
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Livorsi
authors.affiliation: Department of Internal Medicine, University of Utah School of Medicine, Utah.|Veterans Affairs Salt Lake City Health Care System, Utah.
authors.forename: Makoto
authors.initials: M
authors.lastname: Jones
authors.affiliation: Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Justin P
authors.initials: JP
authors.lastname: Albertson
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Rajeshwari
authors.initials: R
authors.lastname: Nair
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.
authors.forename: Amy M J
authors.initials: AMJ
authors.lastname: O'Shea
authors.affiliation: Department of Internal Medicine, Carver College of Medicine, University of Iowa.|Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, Iowa.|Department of Epidemiology, College of Public Health, University of Iowa.
authors.forename: Marin L
authors.initials: ML
authors.lastname: Schweizer
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus; D016896:Treatment Outcome; D047090:beta-Lactams / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams
keywords: MSSA; bacteremia; cefazolin; nafcillin; treatment