title: Predicting mortality among older adults hospitalized for community-acquired pneumonia: an enhanced confusion, urea, respiratory rate and blood pressure score compared with pneumonia severity index.
abstract: OBJECTIVE
  Pneumonia Severity Index (PSI) predicts mortality better than Confusion, Urea >7 mmol/L, Respiratory rate >30/min, low Blood pressure: diastolic blood pressure <60 mm Hg or systolic blood pressure <90 mm Hg, and age >65 years (CURB-65) for community-acquired pneumonia (CAP) but is more cumbersome. The objective was to determine whether CURB enhanced with a small number of additional variables can predict mortality with at least the same accuracy as PSI.
  
  
  METHODS
  Retrospective review of medical records and administrative data of adults aged 55 years or older hospitalized for CAP over 1 year from three hospitals.
  
  
  RESULTS
  For 1052 hospital admissions of unique patients, 30-day mortality was 17.2%. PSI class and CURB-65 predicted 30-day mortality with area under curve (AUC) of 0.77 (95% confidence interval (CI): 0.73-0.80) and 0.70 (95% CI: 0.66-0.74) respectively. When age and three co-morbid conditions (metastatic cancer, solid tumours without metastases and stroke) were added to CURB, the AUC improved to 0.80 (95% CI: 0.77-0.83). Bootstrap validation obtained an AUC estimate of 0.78, indicating negligible overfitting of the model. Based on this model, a clinical score (enhanced CURB score) was developed that had possible values from 5 to 25. Its AUC was 0.79 (95% CI: 0.76-0.83) and remained similar to that of PSI class.
  
  
  CONCLUSIONS
  An enhanced CURB score predicted 30-day mortality with at least the same accuracy as PSI class did among older adults hospitalized for CAP. External validation of this score in other populations is the next step to determine whether it can be used more widely.
authors.affiliation: Department of Respiratory and Critical Care Medicine Geriatric Medicine, Seng Hospital National Healthcare, Singapore. john_abisheganaden@ttsh.com.sg
authors.forename: John
authors.initials: J
authors.lastname: Abisheganaden
authors.forename: Yew Yoong
authors.initials: YY
authors.lastname: Ding
authors.forename: Wai-Fung
authors.initials: WF
authors.lastname: Chong
authors.forename: Bee-Hoon
authors.initials: BH
authors.lastname: Heng
authors.forename: Tow Keang
authors.initials: TK
authors.lastname: Lim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001794:Blood Pressure; D017714:Community-Acquired Infections / Q000401:mortality*; D015897:Comorbidity; D003221:Confusion / Q000453:epidemiology*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011014:Pneumonia / Q000401:mortality*; D056152:Respiratory Rate; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014508:Urea / Q000097:blood*
chemical_list: D014508:Urea