Propensity score-matched analysis comparing the therapeutic efficacies of cefazolin and extended-spectrum cephalosporins as appropriate empirical therapy in adults with community-onset Escherichia coli, Klebsiella spp. and Proteus mirabilis bacteraemia

Int J Antimicrob Agents. 2016 Dec;48(6):712-718. doi: 10.1016/j.ijantimicag.2016.09.015. Epub 2016 Oct 26.


In this study, the therapeutic efficacy of cefazolin was compared with that of extended-spectrum cephalosporins (ESCs) (cefotaxime, ceftriaxone and ceftazidime) as appropriate empirical therapy in adults with community-onset monomicrobial bacteraemia caused by Escherichia coli, Klebsiella spp. or Proteus mirabilis (EKP). Compared with cefazolin-treated patients (n = 135), significantly higher proportions of patients in the ESC treatment group (n = 456) had critical illness at bacteraemia onset (Pitt bacteraemia score ≥4) and fatal co-morbidities (McCabe classification). Of the 591 patients, 121 from each group were matched using propensity score matching (PSM) based on the following independent predictors of 28-day mortality: fatal co-morbidities (McCabe classification); Pitt bacteraemia score ≥4 at bacteraemia onset; initial syndrome of septic shock; and bacteraemia due to pneumonia. After appropriate PSM, no significant differences were observed in the early clinical failure rate (10.7% vs. 7.4%; P = 0.37), the proportion of critical illness (Pitt bacteraemia score ≥4) (0% vs. 0%; P = 1.00) and defervescence (52.6% vs. 42.6%; P = 0.13) on Day 3 between the cefazolin and ESC treatment groups. Similarly, no significant differences were observed in the mean of time to defervescence (4.1 days vs. 4.9 days; P = 0.15), late clinical failure rate (18.2% vs. 10.7%; P = 0.10) and 28-day crude mortality rate (0.8% vs. 3.3%; P = 0.37) between the two groups. These data suggest that the efficacy of cefazolin is similar to that of ESCs when used as appropriate empirical antimicrobial treatment for community-onset EKP bacteraemia.

Keywords: Cefazolin; Community-onset bacteraemia; Escherichia coli; Extended-spectrum cephalosporin; Klebsiella spp; Proteus mirabilis.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / drug therapy*
  • Bacteremia / mortality
  • Cephalosporins / therapeutic use*
  • Cohort Studies
  • Community-Acquired Infections / drug therapy*
  • Community-Acquired Infections / mortality
  • Escherichia coli Infections / drug therapy*
  • Escherichia coli Infections / mortality
  • Female
  • Humans
  • Klebsiella Infections / drug therapy*
  • Klebsiella Infections / mortality
  • Male
  • Middle Aged
  • Propensity Score
  • Proteus Infections / drug therapy*
  • Proteus Infections / mortality
  • Proteus mirabilis
  • Retrospective Studies
  • Survival Analysis
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Cephalosporins