title: Accuracy of a sequential approach to identify young febrile infants at low risk for invasive bacterial infection.
abstract: BACKGROUND
  Much effort has been put in the past years to create and assess accurate tools for the management of febrile infants. However, no optimal strategy has been so far identified. A sequential approach evaluating, first, the appearance of the infant, second, the age and result of the urinanalysis and, finally, the results of the blood biomarkers, including procalcitonin, may better identify low risk febrile infants suitable for outpatient management.
  
  
  OBJECTIVE
  To assess the value of a sequential approach ('step by step') to febrile young infants in order to identify patients at a low risk for invasive bacterial infections (IBI) who are suitable for outpatient management and compare it with other previously described strategies such as the Rochester criteria and the Lab-score.
  
  
  METHODS
  A retrospective comparison of three different approaches (step by step, Lab-score and Rochester criteria) was carried out in 1123 febrile infants less than 3 months of age attended in seven European paediatric emergency departments. IBI was defined as isolation of a bacterial pathogen from the blood or cerebrospinal fluid.
  
  
  RESULTS
  Of the 1123 infants (IBI 48; 4.2%), 488 (43.4%) were classified as low-risk criteria according to the step by step approach (vs 693 (61.7%) with the Lab-score and 458 (40.7%) with the Rochester criteria). The prevalence of IBI in the low-risk criteria patients was 0.2% (95% CI 0% to 0.6%) using the step by step approach; 0.7% (95% CI 0.1% to 1.3%) using the Lab-score; and 1.1% (95% CI 0.1% to 2%) using the Rochester criteria. Using the step by step approach, one patient with IBI was not correctly classified (2.0%, 95% CI 0% to 6.12%) versus five using the Lab-score or Rochester criteria (10.4%, 95% CI 1.76% to 19.04%).
  
  
  CONCLUSIONS
  A sequential approach to young febrile infants based on clinical and laboratory parameters, including procalcitonin, identifies better patients more suitable for outpatient management.
authors.affiliation: Pediatric Emergency Department, Cruces University Hospital, University of the Basque Country, Bilbao, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Mintegi
authors.affiliation: Department of Pediatrics, University of Padova, Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bressan
authors.affiliation: Pediatric Emergency Department, Cruces University Hospital, University of the Basque Country, Bilbao, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: Gomez
authors.affiliation: Ospedale Ca'Foncello, Treviso, Italy.
authors.forename: Liviana
authors.initials: L
authors.lastname: Da Dalt
authors.affiliation: 12 de Octubre University Hospital, Madrid, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Blázquez
authors.affiliation: Donostia University Hospital, Donostia, Spain.
authors.forename: Izaskun
authors.initials: I
authors.lastname: Olaciregui
authors.affiliation: Niño Jesús University Hospital, Madrid, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: de la Torre
authors.affiliation: Navarra Hospital Complex, Pamplona, Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Palacios
authors.affiliation: Ospedale Ca'Foncello, Treviso, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Berlese
authors.affiliation: Pediatric Emergency Department, Cruces University Hospital, University of the Basque Country, Bilbao, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Benito
mesh_terms: D000367:Age Factors; D000553:Ambulatory Care; D001424:Bacterial Infections / Q000150:complications* / Q000175:diagnosis* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D005335:Fever of Unknown Origin / Q000209:etiology* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D007223:Infant; D008297:Male; D018579:Patient Selection; D011498:Protein Precursors / Q000097:blood; D012189:Retrospective Studies; D012306:Risk; D012680:Sensitivity and Specificity; D016482:Urinalysis
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide
keywords: Infectious Diseases