title: Severity assessment criteria recommended by the British Thoracic Society (BTS) for community-acquired pneumonia (CAP) and older patients. Should SOAR (systolic blood pressure, oxygenation, age and respiratory rate) criteria be used in older people? A compilation study of two prospective cohorts.
abstract: OBJECTIVE
  To assess the usefulness of the British Thoracic Society guidelines for severity assessment of community-acquired pneumonia (CAP) in predicting mortality and to explore alternative criteria which could be more useful in older patients.
  
  
  METHODS
  Compilation study of two prospective observational cohorts.
  
  
  METHODS
  A University hospital in Norfolk, UK with a catchment population of 568,000. Subjects were 195 patients (median age = 77 years) who were included in two prospective studies of CAP.
  
  
  METHODS
  All-cause mortality occurring within the 6 week follow-up.
  
  
  RESULTS
  sensitivity, specificity, positive and negative predictive values for study outcome using CURB and CURB-65 were assessed in 189 patients, and CRB-65 in 192 patients out of a total of 195 patients. Our results were comparable with the original study by Lim et al. Although CURB-65 and CRB-65 included age criteria, in effect they did not materially improve the specificity in predicting high-risk patients in both studies. We found that oxygenation measured by ventilation perfusion mismatch (PaO2:FiO2) was the best predictor of outcome in this slightly older cohort [odds ratio (OR) = 0.99 (0.98-0.99), P = 0.0001]. We derived a new set of criteria; SOAR (systolic blood pressure, oxygenation, age and respiratory rate) based on our findings. Their sensitivity, specificity, positive and negative predictive values were 81.0% (58.1-94.6), 59.3% (49.6-68.4), 27.0% (16.6-39.7) and 94.4% (86.2-98.4), respectively, confirming their comparability with existing criteria.
  
  
  CONCLUSIONS
  Our Study confirms the usefulness of currently recommended severity rules for CAP in this older cohort. SOAR criteria may be useful as alternative criteria for a better identification of severe CAP in advanced age where both raised urea level above 7 mmol/l and confusion are common.
authors.affiliation: Department of Medicine for the Elderly, Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, UK. Pkyawmyint@aol.com
authors.forename: Phyo K
authors.initials: PK
authors.lastname: Myint
authors.forename: Ajay V
authors.initials: AV
authors.lastname: Kamath
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Vowler
authors.forename: David N
authors.initials: DN
authors.lastname: Maisey
authors.forename: Brian D W
authors.initials: BD
authors.lastname: Harrison
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001794:Blood Pressure; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D011014:Pneumonia / Q000175:diagnosis*; D012119:Respiration; D012680:Sensitivity and Specificity; D006113:United Kingdom
chemical_list: D010100:Oxygen