A COMPARISON OF THE ACUTE PHYSIOLOGY AND CHRONIC HEALTH EVALUATION (APACHE)-II SCORE AND THE TRAUMA-INJURY SEVERITY SCORE (TRISS) FOR OUTCOME ASSESSMENT IN INTENSIVE-CARE UNIT TRAUMA PATIENTS

Objective: To assess the ability of the Acute Physiology and Chronic H ealth Evaluation (APACHE II) system and Trauma-Injury Severity Scoring (TRISS) system in predicting group mortality in intensive care unit ( ICU) trauma patients. Design: Prospective study. Setting: A Canadian a dult trauma tertiary referral hospital. Patients: Consecutive trauma p atients admitted to the medical-surgical ICU or the neurosurgical ICU. Intervention: None. Measurements and Main Results: For each patient, demographic data, mechanism of injury, and surgical status were collec ted. Revised Trauma Scores and Injury Severity Scores were calculated from emergency room and operative data. The APACHE II score was calcul ated based on the data from the first 24 hrs of ICU admission. The pro bability of death was calculated far each patient based on the APACHE II and TRISS equations. The ability to predict group mortality for APA CHE II and TRISS was assessed by receiver operating characteristic cur ve analysis, two by two decision matrices, and calibration curve analy sis. Four hundred seventy trauma patients were admitted to the ICU. Si xty three (13%) patients died and 407 (87%) survived. There were signi ficant differences between survivors and nonsurvivors in age, Glasgow Coma Scale, Revised Trauma Score, Injury Severity Score, and APACHE II score. By receiver operating characteristic curve analysis, the areas under the curves (+/- SEM) of APACHE II and TRISS were 0.92 +/- 0.02 and 0.89 +/- 0.02, respectively. Using two by two decision matrices wi th a decision criterion of 0.5, the sensitivities, specificities, and percentages correctly classified were 50.8%, 97.3%, and 91.1%, respect ively, for APACHE II, and 50.8%, 97.1%, and 90.9%, respectively, for T RISS. From the calibration curves, the r(2) value was .93 (p = .0001) for APACHE II and .67 (p = .004) for TRISS. Conclusions: Both APACHE I I and TRISS scores were shown to accurately predict group mortality in ICU trauma patients. APACHE II and TRISS may be utilized for quality assurance in ICU trauma patients. However, neither APACHE II nor TRISS provides sufficient confidence for prediction of outcome of individua l patients.