title: Developing a burn injury severity score (BISS): adding age and total body surface area burned to the injury severity score (ISS) improves mortality concordance.
abstract: BACKGROUND
  There is limited research validating the injury severity score (ISS) in burns. We examined the concordance of ISS with burn mortality. We hypothesized that combining age and total body surface area (TBSA) burned to the ISS gives a more accurate mortality risk estimate.
  
  
  METHODS
  Data from the Royal Perth Hospital Trauma Registry and the Royal Perth Hospital Burns Minimum Data Set were linked. Area under the receiver operating characteristic curve (AUC) measured concordance of ISS with mortality. Using logistic regression models with death as the dependent variable we developed a burn-specific injury severity score (BISS).
  
  
  RESULTS
  There were 1344 burns with 24 (1.8%) deaths, median TBSA 5% (IQR 2-10), and median age 36 years (IQR 23-50). The results show ISS is a good predictor of death for burns when ISS≤15 (OR 1.29, p=0.02), but not for ISS>15 (ISS 16-24: OR 1.09, p=0.81; ISS 25-49: OR 0.81, p=0.19). Comparing the AUCs adjusted for age, gender and cause, ISS of 84% (95% CI 82-85%) and BISS of 95% (95% CI 92-98%), demonstrated superior performance of BISS as a mortality predictor for burns.
  
  
  CONCLUSIONS
  ISS is a poor predictor of death in severe burns. The BISS combines ISS with age and TBSA and performs significantly better than the ISS.
authors: Royal Perth Hospital, Australia. Electronic address: Tristancassidy@gmail.com.
authors: J Tristan
authors: JT
authors: Cassidy
authors: Western Australian Institute for Medical Research, University of Western Australia, Australia. Electronic address: Michael.phillips@waimr.uwa.edu.au.
authors: Michael
authors: M
authors: Phillips
authors: Emergency Medicine, Royal Perth Hospital, University of Western Australia, Australia. Electronic address: Daniel.Fatovich@health.wa.gov.au.
authors: Daniel
authors: D
authors: Fatovich
authors: Epidemiology, Burn Injury Research Unit, University of Western Australia, Australia. Electronic address: Janine.Duke@uwa.edu.au.
authors: Janine
authors: J
authors: Duke
authors: Fiona Wood Foundation, Royal Perth Hospital, Australia. Electronic address: Dale.Edgar@health.wa.gov.au.
authors: Dale
authors: D
authors: Edgar
authors: University of Western Australia, Australia. Electronic address: Fiona.Wood@health.wa.gov.au.
authors: Fiona
authors: F
authors: Wood
mesh_terms: D015998:Abbreviated Injury Scale; D000328:Adult; D000367:Age Factors; D019540:Area Under Curve; D001830:Body Surface Area; D002056:Burns / Q000175:diagnosis* / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D055815:Young Adult
keywords: Burn; ISS; Injury severity score; Mortality; Trauma