Integration of GFAP/UCH-L1 Testing into an Emergency Department Concussion Pathway and Calculator to Model TBI Biomarker Impact on Time.

Mild traumatic brain injury (mTBI) accounts for 70-90% of all TBI cases and represents a significant burden on emergency departments (EDs) across the United States. Despite its prevalence, mTBI evaluation remains heavily dependent on head computed tomography (CT), contributing to imaging overuse, increased health care costs, and unnecessary radiation exposure. The Food and Drug Administration-cleared i-STAT® TBI Plasma cartridge offers a promising alternative by identifying patients who may not require CT imaging. However, the real-world diagnostic performance and impact on imaging utilization remain underexplored. This study evaluated the clinical accuracy of the TBI plasma cartridge and its influence on CT use following implementation in a high-volume ED. A retrospective study was conducted at an academic Level-1 trauma center. The first phase involved analytical validation of the test, benchmarked against the Alerting of Traumatic Brain Injury (ALERT-TBI) trial; the second assessed its clinical impact following implementation. Adult patients with mild head trauma (Glasgow Coma Scale [GCS] 13-15) presenting within 12 h of injury were included. Diagnostic accuracy metrics were calculated, and a modeling framework estimated turnaround time (TAT) implications under varying CT rule-out rates. A total of 178 patients were included. During validation, 70 patients underwent both CT and TBI biomarker testing. The TBI biomarker cartridge demonstrated a sensitivity of 91.7%, specificity of 43.1%, and a negative predictive value (NPV) of 96.2% for detecting intracranial injury. In the implementation phase, 108 patients were tested. Of the 60 patients (55.6%) with nonelevated biomarker results, 40 still received CT scans, none of which revealed intracranial hemorrhage. The test contributed to the avoidance of 20 CT scans (18.5%), reflecting a measurable reduction in unnecessary imaging. The TBI biomarker cartridge demonstrated high sensitivity and NPV, reinforcing its impact as a safe, rapid tool to reduce unnecessary CT imaging in mTBI evaluation. While underutilized, its integration into clinical workflows led to measurable reductions in imaging. To accelerate real-world implementation, this study introduces a robust toolkit-featuring an ED throughput calculator and a detailed clinical workflow-to guide EDs in seamlessly integrating biomarker-based decision-making. Implementation of ED point-of-care TBI biomarker testing can lead to reduced CT utilization and shorter length of stay. These resources not only optimize ED efficiency but also advance safer, targeted care by reducing radiation exposure for patients with head trauma.