Citation

Le TD, Orman JA, Stockinger ZT, Spott MA, West SA, Mann-Salinas EA, Chung KK, Gross KR. J. Trauma Acute Care Surg. 2016; 81(1): 114-121.

Affiliation

Joint Trauma System (T.D.L., Z.T.S., M.A.S., S.A.W., K.R.G.) U.S. Army Institute of Surgical Research (T.D.L., J.A.O., E.A.M-S, K.K.C.).

Copyright

(Copyright © 2016, Lippincott Williams and Wilkins)

DOI

10.1097/TA.0000000000001032

PMID

26958797

Abstract

BACKGROUND: The military Injury Severity Score (mISS) was developed to better predict mortality in complex combat injuries, but has yet to be validated.

METHODS: U.S. combat trauma data from Afghanistan and Iraq from January 1, 2003 to December 31, 2014 from the DoD Trauma Registry (DoDTR) were analyzed. mISS, a variation of the ISS, was calculated and compared to standard ISS scores.Receiver Operator Characteristics (ROC), area under the curve (AUC) and Hosmer-Lemeshow statistics were used to discriminate and calibrate between mISS and ISS. Wilcoxon-Mann-Whitney, t-test and Chi-square tests were used and sensitivity and specificity calculated. Logistic regression was used to calculate the likelihood of mortality associated with levels of mISS and ISS overall.

RESULTS: 30,364 patients were analyzed. Most were male (96.8%). Median (IQR) age was 24 (21-29). Battle injuries comprised 65.3%. Penetrating (39.5%) and blunt (54.2%) injury types, and explosion (51%) and gunshot wound (15%) mechanisms predominated. Overall mortality was 6.0%.Median mISS and ISS were similar in survivors (5[2-10] vs. 5 [2-10]) but different in non-survivors, 30 (16-75) vs. 24 (9-23), respectively (P <0.0001). mISS and ISS were discordant in 17.6% (n= 5,352), accounting for 56.2% (n=1016) of deaths. Among cases with discordant severity scores, the median difference between mISS and ISS was 9 (7-16); range 1 to 59. mISS and ISS shared 78% variability (R=0.78).AUC was higher in mISS than ISS overall (0.82 vs. 0.79), for BI (0.79 vs. 0.76) non-BI (0.87 vs. 0.86), penetrating (0.81 vs. 0.77), blunt (0.77 vs. 0.75), explosion (0.81 vs. 0.78), and gunshot (0.79 vs. 0.73), all P < 0.001. Higher mISS and ISS were associated with higher mortality. Compared to ISS, mISS had higher sensitivity (81.2 vs. 63.9) and slightly lower specificity (80.2 vs. 85.7).

CONCLUSION: mISS predicts combat mortality better than ISS. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level III.

Language: en