Contemporary New Zealand coefficients for the Trauma Injury Severity Score: TRISS(NZ).
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.
Schluter
Philip J
PJ
School of Public Health and Psychosocial Studies, AUT University, Auckland, New Zealand. philip.schluter@aut.ac.nz
Cameron
Cate M
CM
Davey
Tamzyn M
TM
Civil
Ian
I
Orchard
Jodie
J
Dansey
Rangi
R
Hamill
James
J
Naylor
Helen
H
James
Carolyn
C
Dorrian
Jenny
J
Christey
Grant
G
Pollard
Cliff
C
McClure
Rod J
RJ
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