title: Validation and clinical implications of the IDSA/ATS minor criteria for severe community-acquired pneumonia.
abstract: BACKGROUND
  The 2007 Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) guidelines defined severe community-acquired pneumonia (CAP) and recommended intensive care unit (ICU) admission when patients fulfilled three out of nine minor criteria. These criteria have not been validated.
  
  
  METHODS
  All patients admitted to our hospital from 2004 to 2007 for CAP were reviewed retrospectively. Patients who fulfilled any IDSA/ATS major criteria for severe CAP at the emergency department (ie, the need for mechanical ventilation or vasopressors) were excluded. The predictive characteristics of the IDSA/ATS minor criteria were compared with those of the Pneumonia Severity Index (PSI) and the CURB-65 score for hospital mortality and ICU admission.
  
  
  RESULTS
  1242 patients were studied (mean age 65.7 years, hospital mortality 14.7%). The areas under the receiver operating characteristic curves for the IDSA/ATS minor criteria were 0.88 (95% CI 0.86 to 0.91) and 0.85 (95% CI 0.81 to 0.88) for predicting hospital mortality and ICU admission, respectively. These were greater than the corresponding areas for the PSI and the CURB-65 score (p < 0.05). The sensitivity, specificity, positive and negative predictive values of the minor criteria were 81.4%, 82.9%, 45.2% and 96.3%, respectively, for hospital mortality and 58.3%, 90.6%, 52.9% and 92.3%, respectively, for ICU admission. The minor criteria were more specific than the PSI and more sensitive than the CURB-65 score for both outcomes.
  
  
  CONCLUSIONS
  These findings support the use of the IDSA/ATS minor criteria to predict hospital mortality and guide ICU admission in inpatients with CAP who do not require emergency mechanical ventilation or vasopressors.
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Medicine, National University Hospital, Singapore.
authors.forename: J
authors.initials: J
authors.lastname: Phua
authors.forename: K C
authors.initials: KC
authors.lastname: See
authors.forename: Y H
authors.initials: YH
authors.lastname: Chan
authors.forename: L S
authors.initials: LS
authors.lastname: Widjaja
authors.forename: N W
authors.initials: NW
authors.lastname: Aung
authors.forename: W J
authors.initials: WJ
authors.lastname: Ngerng
authors.forename: T K
authors.initials: TK
authors.lastname: Lim
mesh_terms: D000368:Aged; D017714:Community-Acquired Infections / Q000175:diagnosis; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D018410:Pneumonia, Bacterial / Q000175:diagnosis*; D011379:Prognosis; D012720:Severity of Illness Index