Accuracy of the new injury severity score in the evaluation of patients with blunt trauma

Background and Objectives: Trauma is a worldwide problem that affects healthy people. Several scales such as Injury Severity Score (ISS) and New ISS (NISS) are used to evaluate trauma patients. This study aimed at evaluating the predictive values of ISS and NISS in predicting the possible mortality rate of trauma patients referred to the emergency department. Methods: This historical cohort study was conducted on multiple trauma patients admitted to the Emergency Department of Imam Reza Hospital in Tabriz, Iran, from January to March 2021. Pearson's regression, Spearman's correlation, and the receiver operating characteristic curve were used to analyze the data. ISS and NISS values were also calculated. Results: In NISS evaluation with the cutoff point of 24, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 93.65%, 82.33%, 51.3%, and 98.49%, respectively. Furthermore, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 3.5 and 0.08, respectively. In ISS evaluation with the cutoff point of 21, the sensitivity, specificity, PPV, and NPV were 88.89%, 82.02%, 49.56%, and 97.38%, respectively. In addition, PLR and NLR were 4.94 and 0.14, respectively. Conclusions: Both ISS and NISS are useful in predicting outcomes in trauma patients, but NISS is more useful and better than ISS and has a higher sensitivity. Due to high sensitivity and a high NPV of NISS, using the high Abbreviated Injury Scale without considering the area of injury can be better and more effective. Therefore, the NISS value works better for patient evaluation and outcome prediction in the emergency department.