Impact of a trauma system on outcome of severely injured patients.

We examined the impact of a trauma system on the survival of patients with a Trauma Score of 8 or less. We compared the observed survival with that predicted using a method that calculates the probability of survival (Ps) based on age, physiologic score, and anatomic severity of injury. Of 3394 patients triaged to trauma centers in a 12-month period, 283 (8.3%) had a Trauma Score of 8 or less. Sufficient data were available in 189 patients with blunt trauma to make the survival comparison. The Ps was 18%; the observed survival was 29%. Of 60 patients with penetrating trauma and complete data, the Ps was 8%; the observed survival was 20%. We attribute the improved survival to the integration of prehospital and hospital care and expeditious surgery.