title: [Prediction of bacteremia in patients with suspicion of infection in emergency room].
abstract: OBJECTIVE
  To evaluate the relationship between some clinical and analytical data and the presence of bacteremia in order to establish a clinical decision rule.
  
  
  METHODS
  All the patients with blood cultures obtained from the emergency room in a two months period were analyzed. Patients were randomly assigned to derivation or validation sets. A logistic regression of the significant values in the univariate analysis was performed and a score obtained. The prevalence of bacteraemia for every score was calculated. The diagnostic efficacy curves and the performance of the predictive model were calculated.
  
  
  RESULTS
  412 patients were enrolled. The blood cultures were positive in 12.8% of them. The significant values in the univariate analysis were Charlson index ≥2 and PCT > 0.4ng/ml. Four groups of increasing risk of bacteraemia were designed, from 0 to 35% in the derivation set and from 2.9% to 27.2% in the validation set. In the diagnostic efficacy curve, the AUC was 0.8 in the derivation set and 0.74 in the validation set. The model presented a negative predictive value of 95.2% in the derivation set and 95.3% in the validation set.
  
  
  CONCLUSIONS
  A model that includes Charlson index and PCT makes possible to define a group of patients with a very low risk of bacteremia.
authors.affiliation: Unidad de Corta Estancia-Urgencias, Hospital Universitari Germans Trias i Pujol, Universitat Autonònoma de Barcelona, Badalona, Barcelona, España. ptudela.germanstrias@gencat.net
authors.forename: Pere
authors.initials: P
authors.lastname: Tudela
authors.forename: Alicia
authors.initials: A
authors.lastname: Lacoma
authors.forename: Cristina
authors.initials: C
authors.lastname: Prat
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Mòdol
authors.forename: Montserrat
authors.initials: M
authors.lastname: Giménez
authors.forename: Jaume
authors.initials: J
authors.lastname: Barallat
authors.forename: Jordi
authors.initials: J
authors.lastname: Tor
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000175:diagnosis* / Q000209:etiology; D004636:Emergency Service, Hospital; D005260:Female; D005544:Forecasting; D006801:Humans; D007239:Infections / Q000150:complications; D008297:Male; D008875:Middle Aged