TRISS determines the probability of survival
(Ps) of a patient from the ISS and RTS using the following formulae:

Where 'b' is calculated from:

The coefficients b0 - b3 are derived from multiple regression analysis
of the Major Trauma Outcome Study (MTOS) database. AgeIndex is 0 if
the patient is below 54 years of age or 1 if 55 years and over. b0
to b3 are coefficients which are different for blunt and penetrating
trauma. If the patient is less than 15, the blunt coefficients are
used regardless of mechanism.

Blunt

Penetrating

b0

-0.4499

-2.5355

b1

0.8085

0.9934

b2

-0.0835

-0.0651

b3

-1.7430

-1.1360

The TRISS calculator determines the probability of survival from
the ISS, RTS and patient's age. ISS and RTS scores can be inputted
independently or calculated from their base parameters.

Abbreviated
Injury Scale:

Head

Face

Chest

Abdomen

Extremity

External

ISS:

Systolic
BP

Resp.
Rate

Coma
Score

RTS:

Age

Probability
of Survival:

Blunt

Penetrating

The TRISS
Calculator will sit as a standalone window on your desktop.