title: Contemporary New Zealand coefficients for the Trauma Injury Severity Score: TRISS(NZ).
abstract: OBJECTIVE
  To develop local contemporary coefficients for the Trauma Injury Severity Score in New Zealand, TRISS(NZ), and to evaluate their performance at predicting survival against the original TRISS coefficients.
  
  
  METHODS
  Retrospective cohort study of adults who sustained a serious traumatic injury, and who survived until presentation at Auckland City, Middlemore, Waikato, or North Shore Hospitals between 2002 and 2006. Coefficients were estimated using ordinary and multilevel mixed-effects logistic regression models.
  
  
  RESULTS
  1735 eligible patients were identified, 1672 (96%) injured from a blunt mechanism and 63 (4%) from a penetrating mechanism. For blunt mechanism trauma, 1250 (75%) were male and average age was 38 years (range: 15-94 years). TRISS information was available for 1565 patients of whom 204 (13%) died. Area under the Receiver Operating Characteristic (ROC) curves was 0.901 (95%CI: 0.879-0.923) for the TRISS(NZ) model and 0.890 (95% CI: 0.866-0.913) for TRISS (P<0.001). Insufficient data were available to determine coefficients for penetrating mechanism TRISS(NZ) models.
  
  
  CONCLUSIONS
  Both TRISS models accurately predicted survival for blunt mechanism trauma. However, TRISS(NZ) coefficients were statistically superior to TRISS coefficients. A strong case exists for replacing TRISS coefficients in the New Zealand benchmarking software with these updated TRISS(NZ) estimates.
authors.affiliation: School of Public Health and Psychosocial Studies, AUT University, Auckland, New Zealand. philip.schluter@aut.ac.nz
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Schluter
authors.forename: Cate M
authors.initials: CM
authors.lastname: Cameron
authors.forename: Tamzyn M
authors.initials: TM
authors.lastname: Davey
authors.forename: Ian
authors.initials: I
authors.lastname: Civil
authors.forename: Jodie
authors.initials: J
authors.lastname: Orchard
authors.forename: Rangi
authors.initials: R
authors.lastname: Dansey
authors.forename: James
authors.initials: J
authors.lastname: Hamill
authors.forename: Helen
authors.initials: H
authors.lastname: Naylor
authors.forename: Carolyn
authors.initials: C
authors.lastname: James
authors.forename: Jenny
authors.initials: J
authors.lastname: Dorrian
authors.forename: Grant
authors.initials: G
authors.lastname: Christey
authors.forename: Cliff
authors.initials: C
authors.lastname: Pollard
authors.forename: Rod J
authors.initials: RJ
authors.lastname: McClure
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015996:Survival Rate / Q000639:trends; D015599:Trauma Severity Indices; D014947:Wounds and Injuries / Q000145:classification* / Q000175:diagnosis / Q000401:mortality; D055815:Young Adult