MILITARY MEDICINE, 187, 9/10:e1136, 2022 A Comparative Study Between Two Combat Injury Severity Scores CAPT Rafael García Cañas, MD*; LT COL Ricardo Navarro Suay, MD, PhD, MS†; MAJ Carlos Rodríguez Moro, MD, PhD*; MAJ Diana M. Crego Vita, MD, PhD*; Javier Arias Díaz, MD, PhD‡; COL Fco. Javier Areta Jim ´ enez, MD§ ABSTRACT Introduction: In recent years, specifc trauma scoring systems have been developed for military casualties. The objective of this study was to examine the discrepancies in severity scores of combat casualties between the Abbreviated Injury Scale 2005- Military (mAIS) and the Military Combat Injury Scale (MCIS) and a review of the current literature on the application of trauma scoring systems in the military setting. Methods: A cross-sectional, descriptive, and retrospective study was conducted between May 1, 2005, and December 31, 2014. The study population consisted of all combat casualties attended in the Spanish Role 2 deployed in Herat (Afghanistan). We used the New Injury Severity Score (NISS) as reference score. Severity of each injury was calculated according to mAIS and MCIS, respectively. The severity of each casualty was calculated according to the NISS based on the mAIS (Military New Injury Severity Score—mNISS) and MCIS (Military Combat Injury Scale-New Injury Severity Score—MCIS-NISS). Casualty severity were grouped by severity levels (mild—scores: 1-8, moderate—scores: 9-15, severe—scores: 16-24, and critical—scores: 25-75). Results: Nine hundred and eleven casualties were analyzed. Most were male (96.37%) with a median age of 27 years. Afghan patients comprised 71.13%. Air medevac was the main casualty transportation method (80.13). Explosion (64.76%) and gunshot wound (34.68%) mechanisms predominated. Overall mortality was 3.51%. Median mNISS and MCIS-NISS were similar in nonsurvivors (36 [IQR, 25-49] vs. [IQR, 25-48], respectively) but different in survivors, 9 (IQR, 4-17) vs. 5 (IQR, 2-13), respectively (P < .0001). The mNISS and MCIS-NISS were discordant in 34.35% (n = 313). Among cases with discordant severity scores, the median difference between mNISS and MCIS-NISS was 9 (IQR, 4-16); range, 1 to 57. Conclusion: Our study fndings suggest that discrepancies in injury severity levels may be observed in one in three of the casualties when using mNISS and MCIS-NISS. INTRODUCTION To improve overall combat casualty care, medical personnel must be able to demonstrate that incorporating new con- cepts and techniques and establishing clinical guidelines and organizational processes are benefcial to the patient’s out- come. This requires reliable and reproducible measurements to quantify the results of these actions; these data must be * Orthopedic and Trauma Surgery Department, Hospital Central de la Defensa “G´ omez Ulla”, 28047 Madrid, Spain † Anesthesiology, Reanimation and Pain Treatment Unit, Hospital Central de la Defensa “G´ omez Ulla”, 28047 Madrid, Spain ‡ Department of Surgery, Complutense University of Madrid, 28040 Madrid, Spain § Head of Orthopedic and Trauma Surgery Unit, Hospital Central de la Defensa “G´ omez Ulla”, 28047 Madrid, Spain The views expressed are solely those of the authors and do not refect the offcial policy or position of the Spanish Ministry of Defense, or the Spanish Government. doi:https://doi.org/10.1093/milmed/usab067 © The Association of Military Surgeons of the United States 2021. All rights reserved. For permissions, please e-mail: journals. permissions@oup.com. internally consistent and must allow direct comparison with other external systems. For this reason, trauma severity scoring were developed. These scores defned as those systems that evaluate, classify, and code injuries are considered as numerical classifcations linked to one or more characteristics of the trauma, as part of the clinical result observed in the patient, in which there is a relationship between the increase in the trauma severity and the increase in the score. Trauma scoring systems are tools that allow reliable, reproducible, and verifable metrics to evalu- ate and categorize the severity of injuries in trauma patients and are an essential item for research and investigation. 1 Intro- duced in the civilian setting more than 30 years ago, in recent years specifc injury scales have been developed for military casualties such as the Abbreviated Injury Scale 2005-Military (mAIS) 2 and the Military Combat Injury Scale (MCIS). 3 Combat casualties represent a challenge for military medicine as they are patients who are usually injured by gunshot or explosives, with multiple complex injuries, in a hostile and austere environment with limited resources. Fur- thermore, the characteristics of the injuries that we will fnd in e1136 MILITARY MEDICINE, Vol. 187, September/October 2022 Downloaded from https://academic.oup.com/milmed/article/187/9-10/e1136/6138194 by guest on 27 August 2022