title: Accuracy of the "traffic light" clinical decision rule for serious bacterial infections in young children with fever: a retrospective cohort study.
abstract: OBJECTIVE
  To determine the accuracy of a clinical decision rule (the traffic light system developed by the National Institute for Health and Clinical Excellence (NICE)) for detecting three common serious bacterial infections (urinary tract infection, pneumonia, and bacteraemia) in young febrile children.
  
  
  METHODS
  Retrospective analysis of data from a two year prospective cohort study
  
  
  METHODS
  A paediatric emergency department.
  
  
  METHODS
  15,781 cases of children under 5 years of age presenting with a febrile illness.
  
  
  METHODS
  Clinical features were used to categorise each febrile episodes as low, intermediate, or high probability of serious bacterial infection (green, amber, and red zones of the traffic light system); these results were checked (using standard radiological and microbiological tests) for each of the infections of interest and for any serious bacterial infection.
  
  
  RESULTS
  After combination of the intermediate and high risk categories, the NICE traffic light system had a test sensitivity of 85.8% (95% confidence interval 83.6% to 87.7%) and specificity of 28.5% (27.8% to 29.3%) for the detection of any serious bacterial infection. Of the 1140 cases of serious bacterial infection, 157 (13.8%) were test negative (in the green zone), and, of these, 108 (68.8%) were urinary tract infections. Adding urine analysis (leucocyte esterase or nitrite positive), reported in 3653 (23.1%) episodes, to the traffic light system improved the test performance: sensitivity 92.1% (89.3% to 94.1%), specificity 22.3% (20.9% to 23.8%), and relative positive likelihood ratio 1.10 (1.06 to 1.14).
  
  
  CONCLUSIONS
  The NICE traffic light system failed to identify a substantial proportion of serious bacterial infections, particularly urinary tract infections. The addition of urine analysis significantly improved test sensitivity, making the traffic light system a more useful triage tool for the detection of serious bacterial infections in young febrile children.
authors: Screening and Test Evaluation Program, School of Public Health, University of Sydney, Sydney 2006, Australia. sukanya.de@health.nsw.gov.au
authors: Sukanya
authors: S
authors: De
authors: Gabrielle J
authors: GJ
authors: Williams
authors: Andrew
authors: A
authors: Hayen
authors: Petra
authors: P
authors: Macaskill
authors: Mary
authors: M
authors: McCaskill
authors: David
authors: D
authors: Isaacs
authors: Jonathan C
authors: JC
authors: Craig
mesh_terms: D001424:Bacterial Infections / Q000175:diagnosis*; D002675:Child, Preschool; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D005334:Fever / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014218:Triage