title: Development and validation of a clinical prediction rule for severe community-acquired pneumonia.
abstract: BACKGROUND
  Objective strategies are needed to improve the diagnosis of severe community-acquired pneumonia in the emergency department setting.
  
  
  OBJECTIVE
  To develop and validate a clinical prediction rule for identifying patients with severe community-acquired pneumonia, comparing it with other prognostic rules.
  
  
  METHODS
  Data collected from clinical information and physical examination of 1,057 patients visiting the emergency department of a hospital were used to derive a clinical prediction rule, which was then validated in two different populations: 719 patients from the same center and 1,121 patients from four other hospitals.
  
  
  RESULTS
  In the multivariate analyses, eight independent predictive factors were correlated with severe community-acquired pneumonia: arterial pH < 7.30, systolic blood pressure < 90 mm Hg, respiratory rate > 30 breaths/min, altered mental status, blood urea nitrogen > 30 mg/dl, oxygen arterial pressure < 54 mm Hg or ratio of arterial oxygen tension to fraction of inspired oxygen < 250 mm Hg, age > or = 80 yr, and multilobar/bilateral lung affectation. From the beta parameter obtained in the multivariate model, a score was assigned to each predictive variable. The model shows an area under the curve of 0.92. This rule proved better at identifying patients evolving toward severe community-acquired pneumonia than either the modified American Thoracic Society rule, the British Thoracic Society's CURB-65, or the Pneumonia Severity Index.
  
  
  CONCLUSIONS
  A simple score using clinical data available at the time of the emergency department visit provides a practical diagnostic decision aid, and predicts the development of severe community-acquired pneumonia.
authors.affiliation: Service of Pneumology, Department of Emergency Medicine, Research Unit, Hospital de Galdakao, Galdako, Bizkaia, Spain. pespana@hgda.osakidetza.net
authors.forename: Pedro P
authors.initials: PP
authors.lastname: España
authors.forename: Alberto
authors.initials: A
authors.lastname: Capelastegui
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Gorordo
authors.forename: Cristobal
authors.initials: C
authors.lastname: Esteban
authors.forename: Mikel
authors.initials: M
authors.lastname: Oribe
authors.forename: Miguel
authors.initials: M
authors.lastname: Ortega
authors.forename: Amaia
authors.initials: A
authors.lastname: Bilbao
authors.forename: José M
authors.initials: JM
authors.lastname: Quintana
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D017714:Community-Acquired Infections / Q000175:diagnosis; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011014:Pneumonia / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis