Injury severity scoring

The wish to predict outcome following injury is as old as human history, but the actual measurement of injury severity began only 40 years ago. Tools are now available to measure both physical injury [the Injury Severity Score (ISS)] and physiologic derangement [the Revised Trauma Score (RTS)], as well as their synergistic combination, into a probability of survival score (TRISS). Although these tools are in daily use in most trauma centers, their predictive power is only mediocre. While adequate for estimation of the trauma severity in populations of patients, these measures have proven inadequate for predicting individual outcomes, and their usefulness in comparing trauma systems and centers has proven problematic. Better alternatives to these tools have been developed, but adoption has been slow because these incremental improvements in predictive power have not been sufficient to allow expanded uses for injury scoring. We now face the possibility that injury scoring can never be robust enough to be either clinically useful or the basis for meaningful comparisons between trauma centers. We should continue our quest for improved outcome prediction, but we must resist demands that injury scoring systems be extended into realms where they may detract from intelligent discourse or damage clinical practice.