title: Validation of the "Step-by-Step" Approach in the Management of Young Febrile Infants.
abstract: A sequential approach to young febrile infants on the basis of clinical and laboratory parameters, including procalcitonin, was recently described as an accurate tool in identifying patients at risk for invasive bacterial infection (IBI). Our aim was to prospectively validate the Step-by-Step approach and compare it with the Rochester criteria and the Lab-score.
  
  
  
  Prospective study including infants ≤90 days with fever without source presenting in 11 European pediatric emergency departments between September 2012 and August 2014. The accuracy of the Step-by-Step approach, the Rochester criteria, and the Lab-score in identifying patients at low risk of IBI (isolation of a bacterial pathogen in a blood or cerebrospinal fluid culture) was compared.
  
  
  
  Eighty-seven of 2185 infants (4.0%) were diagnosed with an IBI. The prevalence of IBI was significantly higher in infants classified as high risk or intermediate risk according to the Step by Step than in low risk patients. Sensitivity and negative predictive value for ruling out an IBI were 92.0% and 99.3% for the Step by Step, 81.6% and 98.3% for the Rochester criteria, and 59.8% and 98.1% for the Lab-score. Seven infants with an IBI were misclassified by the Step by Step, 16 by Rochester criteria, and 35 by the Lab-score.
  
  
  
  We validated the Step by Step as a valuable tool for the management of infants with fever without source in the emergency department and confirmed its superior accuracy in identifying patients at low risk of IBI, compared with the Rochester criteria and the Lab-score.
authors.affiliation: Pediatric Emergency Department, Cruces University Hospital, Bilbao, Spain; University of the Basque Country, Bilbao, Spain; borja.gomezcortes@osakidetza.eus.
authors.forename: Borja
authors.initials: B
authors.lastname: Gomez
authors.affiliation: Pediatric Emergency Department, Cruces University Hospital, Bilbao, Spain; University of the Basque Country, Bilbao, Spain;
authors.forename: Santiago
authors.initials: S
authors.lastname: Mintegi
authors.affiliation: Pediatric Emergency Unit - Department of Woman's and Child Health, University of Padova, Italy;
authors.forename: Silvia
authors.initials: S
authors.lastname: Bressan
authors.affiliation: Ca'Foncello Hospital, Treviso, Italy; and.
authors.forename: Liviana
authors.initials: L
authors.lastname: Da Dalt
authors.affiliation: Pediatric Emergency Division, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Alain
authors.initials: A
authors.lastname: Gervaix
authors.affiliation: Pediatric Emergency Division, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Laurence
authors.initials: L
authors.lastname: Lacroix
mesh_terms: D000465:Algorithms; D001170:Arthritis, Infectious / Q000150:complications / Q000175:diagnosis; D016470:Bacteremia / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D000066491:Clinical Decision-Making / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D005334:Fever / Q000209:etiology*; D006305:Health Status Indicators; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016920:Meningitis, Bacterial / Q000134:cerebrospinal fluid / Q000150:complications / Q000175:diagnosis*; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity