COMPARISON OF THE APACHE-III, APACHE-II AND GLASGOW COMA SCALE IN ACUTE HEAD-INJURY FOR PREDICTION OF MORTALITY AND FUNCTIONAL OUTCOME

Objectives: This study examines the efficacy of the predicting power f or hospital mortality and functional outcome of three different scorin g systems for head injury in a neurosurgical intensive care unit (NICU ). Design: On the day of admission, data were collected from each pati ent to compute the Acute Physiology, Age, and Chronic Health Evaluatio n (APACHE) II and III, and Glasgow Coma Scale (GCS) scores. Hospital m ortality was defined as the deaths of patients before discharge from h ospital. Early mortality was defined as death before the 14th day afte r admission. Late mortality was defined as death after the 15th day fr om admission. Functional outcome was evaluated by Index of Independenc e in Activities of Daily Living (Index of ADL). Setting: An 8-bed NICU in a 1270-bed medical center in Taichung Veterans General Hospital. P atients and participants: Two hundred non-selected patients with acute head injury were included in our study in a consecutive period of 2 y ears. Patients less than 14 years old were not included. Interventions : None. Measurements and Results: Sensitivity, specificity and correct prediction outcome were measured by the chi-square method in three sc oring systems. The Youden index was also obtained. The best cut-off po int in each scoring system was determined by the Youden index. The dif ference in Youden index was calculated by Z score. A difference was al so considered if the probability value was less than 0.05. The area un der Receiver Operating Characteristic (ROC) curve was computed. Then t he area under ROC of each scoring system was compared by Z score. Ther e was statistical significance if p was less than 0.05. For prediction of hospital mortality, the best cut-off points are 55 for APACHE III, 17 for APACHE II and 5 for GCS. The correct prediction outcome is 82. 4% in APACHE II, 78.4% in APACHE II and 81.9% in the GCS, The Youden i ndex has best cut-off points at 0.68 for APACHE III, 0.59 for APACHE I I, and 0.56 for GCS. The area under Receiver Operating Characteristic (ROC) curve is 0.90 in the APACHE III, 0.84 in the APACHE II and 0.86 in the GCS, There are no statistical differences among APACHE III and II, and GCS in terms of correct prediction outcome, Youden Index and t he area under the ROC curve. Other physiological variables excluding G CS in APACHE III and II (AP III-GCS, AP II-GCS) have less statistical value in the determination of mortality for acute head injury. For the prediction of late mortality, APACHE III and II yield significantly b etter results in the area under the ROC curve, correct prediction and Youden index than those of GCS. Other physiological variables (AP III- GCS and AP II-GCS) play an important role in the prediction of late mo rtality in APACHE scores. For prediction of the functional outcome of surviving patients with acute head injury, the APACHE III yields the b est results of correct prediction outcome, Youden index and the area u nder the ROC curve. Conclusion: The APACHE III and II may not replace the role of GCS in cases of acute head injury for hospital or early mo rtality assessment. But for prediction of the late mortality, the APAC HE III and II have better accuracy than GCS. Other physiological varia bles excluding GCS in the APACHE system play a crucial contribution fo r late mortality. GCS is simple, less time-consuming and economical fo r patients with acute head injury for the prediction of hospital and e arly mortality. The APACHE III provides better prediction for severe m orbidity than GCS and APACHE II. Therefore, the APACHE III provides a good assessment not only for hospital and late mortality, but also for functional outcome.