Defining Mild Traumatic Brain Injury: From Research Definition to Clinical Practice.

INTRODUCTION: Approximately 75% of traumatic brain injuries (TBIs) qualify as mild. However, there exists no universally agreed upon definition for mild TBI (mTBI). Consequently, treatment guidelines for this group are lacking. The Center for Disease Control (CDC), American College of Rehabilitation Medicine (ACRM), Veterans Affairs and Department of Defense (VA/DoD), Eastern Association for the Surgery of Trauma (EAST), and the University of Arizona's Brain Injury Guidelines (BIG) have each published differing definitions for mTBI. The aim of this study was to compare the ability of these definitions to correctly classify mTBI patients in the acute care setting.

METHODS: A single-center, retrospective cohort study comparing the performance of the varying definitions of mTBI was performed at a Level I trauma center from August 2015 to December 2018. Definitions were compared by sensitivity, specificity, positive predictive value, negative predictive value, as well as overtriage and undertriage rates. Finally, a cost-savings analysis was performed.

RESULTS: We identified 596 patients suffering blunt TBI with Glasgow Coma Scale 13-15. The CDC/ACRM definitions demonstrated 100% sensitivity but 0% specificity along with the highest rate of undertriage and TBI-related mortality. BIG 1 included nearly twice as many patients than EAST and VA/DoD while achieving a superior positive predictive value and undertriage rate.

CONCLUSIONS: The BIG definition identified a larger number of patients compared to the VA/DoD and EAST definitions while having an acceptable and more accurate overtriage and undertriage rate compared to the CDC and ACRM. By eliminating undertriage and minimizing overtriage rates, the BIG maintains patient safety while enhancing the efficiency of healthcare systems. Using the BIG definition, a cost savings of $395,288.95-$401,263.95 per year could be obtained at our level 1 trauma facility without additional mortality.