title: A prediction rule for estimating the risk of bacteremia in patients with community-acquired pneumonia.
abstract: BACKGROUND
  We endeavored to construct a simple score based entirely on epidemiological and clinical variables that would stratify patients who require hospital admission because of community-acquired pneumonia into groups with a low or high risk of developing bacteremia.
  
  
  METHODS
  Derivation and internal validation cohorts were obtained by retrospective analysis of a database that included 3116 consecutive patients with community-acquired pneumonia from 2 university hospitals. Potential predictive factors were determined by means of a multivariate logistic regression equation applied to a cohort consisting of 60% of the patients. Points were assigned to significant parameters to generate the score. It was then internally validated with the remaining 40% of patients and was externally validated using an independent multicenter cohort of 1369 patients.
  
  
  RESULTS
  The overall rates of bacteremia were 12%-16% in the cohorts. The clinical probability estimate of developing bacteremia was based on 6 variables: liver disease, pleuritic pain, tachycardia, tachypnea, systolic hypotension, and absence of prior antibiotic treatment. For the score, 1 point was assigned to each predictive factor. In the derivation cohort, a cutoff score of 2 best identified the risk of bacteremia. In the validation cohorts, rates of bacteremia were <8% for patients with a score 1 (43%-49% of patients), whereas blood culture results were positive in 14%-63% of cases for patients with a score 2.
  
  
  CONCLUSIONS
  This clinical score, based on readily available and objective variables, provides a useful tool to predict bacteremia. The score has been internally and externally validated and may be useful to guide diagnostic decisions for community-acquired pneumonia.
authors: Services of 1Internal Medicine, Hospital Universitari Arnau de Vilanova, Universitat de Lleida, Institut de Recerca Biomèdia de Lleida, Ciber de Enfermedades Respiratorias, Lleida, Spain. mfalguera@comll.cat
authors: Miquel
authors: M
authors: Falguera
authors: Javier
authors: J
authors: Trujillano
authors: Sílvia
authors: S
authors: Caro
authors: Rosario
authors: R
authors: Menéndez
authors: Jordi
authors: J
authors: Carratalà
authors: Agustín
authors: A
authors: Ruiz-González
authors: Manuel
authors: M
authors: Vilà
authors: Mercè
authors: M
authors: García
authors: José Manuel
authors: JM
authors: Porcel
authors: Antoni
authors: A
authors: Torres
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000453:epidemiology*; D017714:Community-Acquired Infections / Q000150:complications* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000150:complications*; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors