Secondary Logo

Institutional members access full text with Ovid®

Share this article on:

Characterizing injury severity in nonaccidental trauma

Does Injury Severity Score miss the mark?

Brown, Joshua B., MD; Gestring, Mark L., MD; Leeper, Christine M., MD; Sperry, Jason L., MD; Peitzman, Andrew B., MD; Billiar, Timothy R., MD; Gaines, Barbara A., MD

Journal of Trauma and Acute Care Surgery: October 2018 - Volume 85 - Issue 4 - p 668–673
doi: 10.1097/TA.0000000000001841

BACKGROUND Children suffering nonaccidental trauma (NAT) are at high risk of death. It is unclear whether markers of injury severity for trauma center/system benchmarking such as Injury Severity Score (ISS) adequately characterize this. Our objective was to evaluate mortality prediction of ISS in children with NAT compared with accidental trauma (AT).

METHODS Pediatric patients younger than 16 years from the Pennsylvania state trauma registry 2000 to 2013 were included. Logistic regression predicted mortality from ISS for NAT and AT patients. Multilevel logistic regression determined the association between mortality and ISS while adjusting for age, vital signs, and injury pattern in NAT and AT patients. Similar models were performed for head Abbreviated Injury Scale (AIS). Sensitivity analysis examined impaired functional independence at discharge as an alternate outcome.

RESULTS Fifty thousand five hundred seventy-nine patients were included with 1,866 (3.7%) NAT patients. Nonaccidental trauma patients had a similar rate of mortality at an ISS of 13 as an ISS of 25 for AT patients. Nonaccidental trauma patients also have higher mortality for a given head AIS level (range, 1.2-fold to 5.9-fold higher). Injury Severity Score was a significantly greater predictor of mortality in AT patients (adjusted odds rations [AOR], 1.14; 95% confidence interval [CI], 1.13–1.15; p < 0.01) than NAT patients (AOR, 1.09; 95% CI, 1.07–1.12; p < 0.01) per 1-point ISS increase, while head injury was a significantly greater predictor of mortality in NAT patients (AOR, 3.48; 95% CI, 1.54–8.32; p < 0.01) than AT patients (AOR, 1.21; 95% CI, 0.95–1.45; p = 0.12). Nonaccidental trauma patients had a higher rate of impaired functional independence at any given ISS or head AIS level than AT patients.

CONCLUSION Nonaccidental trauma patients have higher mortality and impaired function at a given ISS/head AIS than AT patients. Conventional ISS thresholds may underestimate risk and head injury is a more important predictor of mortality in the NAT population. These findings should be considered in system performance improvement and benchmarking efforts that rely on ISS for injury characterization.

LEVEL OF EVIDENCE Epidemiologic study, level III.

From the Division of Trauma and General Surgery, Department of Surgery (J.B.B., C.M.L., J.L.S., A.B.P., T.R.B.), University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; Division of Acute Care Surgery, Department of Surgery (M.L.G.), University of Rochester Medical Center, Rochester, New York; Golisano Children's Hospital (M.L.G.), University of Rochester, Rochester, New York; and Division of Pediatric General and Thoracic Surgery, Department of Surgery (C.M.L., B.A.G.), Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.

Submitted: December 9, 2017, Revised: January 20, 2018, Accepted: January 26, 2018, Published online: February 20, 2018.

Address for reprints: Joshua B. Brown, MD, Division of Trauma and General Surgery, Department of Surgery University of Pittsburgh Medical Center 200 Lothrop Street, Pittsburgh, PA 15213; email:

This article was presented as an oral podium presentation at the 4th annual meeting of the Pediatric Trauma Society in Charleston, SC, November 2–4, 2017.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML text of this article on the journal’s Web site (

© 2018 Lippincott Williams & Wilkins, Inc.