Clinical Risk Score for Prediction of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Bloodstream Isolates

Infect Control Hosp Epidemiol. 2017 Mar;38(3):266-272. doi: 10.1017/ice.2016.292. Epub 2016 Dec 19.

Abstract

OBJECTIVE To develop a risk score to predict probability of bloodstream infections (BSIs) due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBLE). DESIGN Retrospective case-control study. SETTING Two large community hospitals. PATIENTS Hospitalized adults with Enterobacteriaceae BSI between January 1, 2010, and June 30, 2015. METHODS Multivariate logistic regression was used to identify independent risk factors for ESBLE BSI. Point allocation in extended-spectrum β-lactamase prediction score (ESBL-PS) was based on regression coefficients. RESULTS Among 910 patients with Enterobacteriaceae BSI, 42 (4.6%) had ESBLE bloodstream isolates. Most ESBLE BSIs were community onset (33 of 42; 79%), and 25 (60%) were due to Escherichia coli. Independent risk factors for ESBLE BSI and point allocation in ESBL-PS included outpatient procedures within 1 month (adjusted odds ratio [aOR], 8.7; 95% confidence interval [CI], 3.1-22.9; 1 point), prior infections or colonization with ESBLE within 12 months (aOR, 26.8; 95% CI, 7.0-108.2; 4 points), and number of prior courses of β-lactams and/or fluoroquinolones used within 3 months of BSI: 1 course (aOR, 6.3; 95% CI, 2.7-14.7; 1 point), ≥2 courses (aOR, 22.0; 95% CI, 8.6-57.1; 3 points). The area under the receiver operating characteristic curve for the ESBL-PS model was 0.86. Patients with ESBL-PSs of 0, 1, 3, and 4 had estimated probabilities of ESBLE BSI of 0.7%, 5%, 24%, and 44%, respectively. Using ESBL-PS ≥3 to indicate high risk provided a negative predictive value of 97%. CONCLUSIONS ESBL-PS estimated patient-specific risk of ESBLE BSI with high discrimination. Incorporation of ESBL-PS with acute severity of illness may improve adequacy of empirical antimicrobial therapy and reduce carbapenem utilization. Infect Control Hosp Epidemiol 2017;38:266-272.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anti-Bacterial Agents / therapeutic use
  • Bacteremia / drug therapy*
  • Bacteremia / epidemiology
  • Case-Control Studies
  • Enterobacteriaceae / enzymology
  • Enterobacteriaceae / isolation & purification*
  • Enterobacteriaceae Infections / drug therapy*
  • Female
  • Fluoroquinolones / therapeutic use*
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • South Carolina
  • beta-Lactamases / biosynthesis
  • beta-Lactams / therapeutic use*

Substances

  • Anti-Bacterial Agents
  • Fluoroquinolones
  • beta-Lactams
  • beta-Lactamases