The Cardiovascular
ToolsCalculators

Trauma Score and Injury Severity Score (TRISS)

Trauma Score and Injury Severity Score (TRISS)
Mechanism
Age
years
Glasgow Coma Scale
points
Systolic blood pressure
mmHg
Respiratory rate
/min
Injury Severity Score (ISS)
points
Complete the fields above to see the result.

When to use

  • Benchmarking observed versus expected trauma survival for quality assurance and trauma registry outcome comparisons.

Formula

RTS = 0.9368xGCS-coded + 0.7326xSBP-coded + 0.2908xRR-coded (each coded 0-4 by standard bands). b = b0 + b1xRTS - b2xISS - b3xAgeIndex (AgeIndex 0 if age<=54, else 1), using blunt coefficients (b0=-0.4499, b1=0.8085, b2=0.0835, b3=1.7430) or penetrating coefficients (b0=-2.5355, b1=0.9934, b2=0.0651, b3=1.1360). Probability of survival Ps = 1/(1+e^-b).

Pearls and pitfalls

  • A trauma registry tool for comparing observed to predicted mortality (e.g. via the W-statistic), not a bedside triage tool.
  • Coefficients derived from the Major Trauma Outcome Study (MTOS) database and may not generalise to all populations.

References

  1. Boyd CR, Tolson MA, Copes WS. Evaluating trauma care: the TRISS method. J Trauma. 1987;27(4):370-8.