Building upon our long-standing and highly successful EMS research laboratory that has specifically focused on the triage of injured patients and the prehospital care of older patients and employing a combination of qualitative and quantitative methods, we will collect data from a large, multi-county catchment area that includes multiple EMS agencies, urban and rural environments, as well as trauma centers and non-trauma centers. In this study, we will: 1) identify candidate neurologic scales to maximize detection of high-risk older adult TBI patients; 2) characterize the current trauma triage process used by EMS providers to identify older patients with suspected TBI and patients taking anticoagulants and/or platelet inhibitors; 3) assess the public health burden of TBI among older adult EMS patients taking anticoagulants and/or platelet inhibitors; 4) assess the predictive ability of novel prehospital-based neurologic screening strategies to identify high-risk older adult TBI patients in the prehospital setting who require TBI-related trauma center care. Findings from this study have the potential to shift clinical practice in the prehospital setting by informing future recommendations for the identification of TBI among older adults taking anticoagulants or platelet inhibitors.