Rescue

1: Study Instruments

Therapeutic Intervention Scoring System (TISS)10,11 - a method of estimating the stability of a patient's condition and the need for critical care from the interventions required. It has also been adapted for use in HEMS.12,13 Injury severity score (ISS)14 - an anatomical summary scoring system whereby injured patients are assigned values of 1 to 75 based on the sum of squared scores of 1 (minor injury) to 5 (critical injury) for the (up to) three most severely injured regions. Three regions with a score of 5 gives the maximum total score of 75. An ISS of 16 (which corresponds to an average mortality rate of 10%) or more is taken as defining major trauma.15 Trauma Score - Injury Severity Score (TRISS) - a method of predicting the prognosis of trauma patients16 which has become an accepted tool internationally for determining the impact of HEMS on trauma mortality.6-9,17 It combines a physiological scoring system, the revised trauma score (RTS),18,19 with the injury severity score (ISS).14 Major Trauma Outcome Study (MTOS)15,20 - a study in which TRISSscoring, age and mechanism of injury were used to calculate norms for survival in a regression analysis of 80000 patients with trauma in 139 North American hospitals. The norms were updated in 1990.20 Patients with a survival probability (Ps) of 0.5 or less are expected to die and those with a Ps greater than 0.5 are expected to live.17 The Major Trauma Outcome Study cohort has been widely used as a benchmark for comparing outcomes in patients with trauma using the TRISS methodology. It can be used to identify unexpected outcomes in populations and in individual patients.

Back to article | Home | Issues | MJA shop | Terms of use | MJA Careers | More... | Contact | Topics | Search | RSS  mja.com.au | The Medical Journal of Australia   Readers may print a single copy for personal use. No further reproduction or distribution of the articles should proceed without the permission of the publisher. For permission, contact the Australasian Medical Publishing Company. Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au>". <URL: http://www.mja.com.au/> © 1998 Medical Journal of Australia. We appreciate your comments.