Co-Principal Investigator: Ashley Weaver, PhD, Wake Forest University; Mark R. Zonfrillo, MD, MSCE, Children's Hospital of Philadelphia (current affiliation: Hasbro Children’s Hospital/Brown University)

Below is an executive summary of this project. Please note that this summary describes results and interpretation that may not be final. Final interpretation of results will be in the peer-reviewed literature.

The Abbreviated Injury Scale (AIS) is considered the global system of choice for injury data collection and has become the basis for a number of derivative scales in use. However, the AIS is largely based on mortality risk, and there may be age-specific differences in injury outcomes. Such differences may become evident by quantifying time sensitivity (a measure associated with the urgency with which an injury should be treated), mortality risk (a measure of the associated mortality and threat to life of an injury), and disability risk (a measure of the associated disability of an injury). No prior study has identified pediatric-specific injuries that vary in these three measures and this could inform future pediatric-specific modifications to the AIS. Therefore, this study aimed to identify the specific injuries that result in varying levels of time sensitivity, mortality risk, and disability risk (both greater and lesser) in children, when compared to adults.

The top 95 percent most frequently occurring AIS 3, 4, and 5 injuries in motor vehicle crashes (MVCs) were identified using the National Automotive Sampling System–Crashworthiness Data System (NASS-CDS) years 2000-2011. Time sensitivity was quantified using expert physician survey data (n=164 experts/n= 12,152 responses) in which physicians were asked to determine whether a particular injury should go to a Level I/II trauma center and the urgency with which that injury required treatment. Time sensitivity was quantified for the pediatric age groups of 0-4 years, 5-9 years, 10-14 years, and 15-18 years and an adult age group of 19+. Mortality risk and a co-injury adjusted mortality risk were calculated using the National Trauma Data Bank (NTDB) years 2002-2011 for the pediatric age groups (18 and under) and years 2002-2006 for the adult age groups of 19-45 years, 46-65 years, and 66+ years. Disability risk and a co-injury adjusted disability risk (DRMAIS) were calculated using NTDB years 2002-2006 for a pediatric age group of 7-18 years and the adult age groups of 19-45 years, 46-65 years, and 66+ years. All three metrics were compared between pediatric age groups versus adult age groups to determine age-specific differences in injury outcomes.

An analysis focusing on MVC head injuries and disability revealed that the pediatric population possessed higher DRMAIS values for brain stem injuries as well as loss of consciousness injuries compared to the adult age groups. Older adults possessed higher co-injury adjusted disability values for contusion/hemorrhage injuries, epidural hemorrhage, intracerebral hemorrhage, skull fracture, and subdural/subarachnoid hemorrhage compared to pediatric patients, adults, and middle adults.

This study demonstrates that there are age-related differences in time sensitivity, mortality risk, and disability risk and, therefore, injury outcomes. Information regarding these metrics is especially crucial for at-risk populations of pediatric patients, as disability and injury outcomes can result in loss of quality life years. These metrics could be used to supplement the assessment of injuries using AIS, especially for injuries that do not necessarily lead to death. In addition, understanding age-related differences in injury outcomes could inform future age-specific modifications to AIS including creation of a pediatric-specific AIS.

Project Team Members

Ryan Barnard, MS, Wake Forest University; Joel Stitzel, PhD, Wake Forest University; Jenn Talton, MS, Wake Forest University

Students

Gretchen Baker, University of Kansas; Samantha Schoell, Wake Forest University

IAB Mentors

Doug Longhitano, American Honda Motor Co., Inc.; Eric Dahle, Evenflo Company Inc.; John Combest, Nissan Technical Center North America Inc.; Hiromasa Tanji, TK Holdings Inc.; Dan Robertson, Toyota USA; Ann Mallory, Transportation Research Center Inc.; Uwe Meissner, Technical Advisor