New Injury Severity Score Is a Better Predictor of Mortality for Blunt Trauma Patients Than the Injury Severity Score

Trauma-related mortality depends on injury severity. Several trauma scores are used to evaluate injury severity. We compared the Injury Severity Score (ISS) and the New Injury Severity Score (NISS) in terms of predicting mortality among hospitalized blunt trauma patients. The data of Al-Ain Hospital Trauma Registry were prospectively collected over 3 years. Data of blunt trauma patients were then analyzed retrospectively. Univariate analysis was used to compare patients who died with those who survived. Sex, age, mechanism of injury, heart rate, systolic blood pressure (SBP), and Glasgow Coma Score (GSC) on arrival at the hospital, ISS, and NISS were studied. Significant factors were then entered into a direct likelihood ratio logistic regression model. Of 2,573 patients in the registry, 2,115 (82.2 %) suffered blunt trauma at a mean (SD) age of 32 (15.3) years. Among them, 1,838 (87 %) were male. Main mechanisms of injury were road traffic collision (vehicle occupants) (32.8 %) and falling from a height (22.4 %). Fifty patients (2.4 %) died. Univariate analysis showed that GCS and SBP at hospital arrival, ISS, NISS, and mechanism of injury significantly affected mortality. Logistic regression model showed that mortality was significantly increased by low GCS (p < 0.0001), high NISS (p < 0.0001), and low SBP (p = 0.006) at hospital arrival. Mortality of blunt trauma in the UAE is significantly affected by high NISS, low GCS, and hypotension. NISS is better than ISS for predicting mortality of blunt trauma patients and may replace it.