TRISS (Trauma & Injury Severity Score)
TRISS (Boyd 1987): the probability of survival after trauma from the Revised Trauma Score, Injury Severity Score, age, and blunt/penetrating mechanism.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Mechanism
- Blunt
- Revised Trauma Score
- 6
- Injury Severity Score
- 25
- Age
- 60
Result: TRISS probability of survival 65.8% (blunt mechanism; RTS 6, ISS 25, age >= 55).
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Mechanism
- Revised Trauma Score
- Injury Severity Score
- Age (years)
How this is calculated
- Model
- Ps = 1/(1 + e^-b), b = b0 + b1*RTS + b2*ISS + b3*AgeIndex (AgeIndex 0 if age < 55, 1 if >= 55). Blunt and penetrating coefficient sets.
- Inputs
- coded Revised Trauma Score (0 to 7.8408) and Injury Severity Score from the live iss-rts tool; mechanism selects the coefficient set.
Boyd CR, Tolson MA, Copes WS. Evaluating trauma care: the TRISS method. Trauma Score and the Injury Severity Score. J Trauma. 1987;27(4):370-378. Coefficients per the MTOS revision (Champion HR, et al). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.