Spaite DW, et al. - To determine if statewide implementation of prehospital traumatic brain injury (TBI) treatment guidelines impacts patient survival following brain trauma, investigators conducted the Excellence in Prehospital Injury Care (EPIC) study on patients sustaining moderate, severe, and critical TBI, with >130 medical emergency agencies throughout Arizona. Patients with moderate to critically severe TBI rushed to trauma centers between January 1, 2007 and June 30, 2015 were included in this statewide, multisystem, intention-to-treat study with the aid of before/after controlled design. Assessment of data was done between October 25, 2017and February 22, 2019. The study (median age 45 years) comprised 14,666 males, 7,181 females, 16,408 whites, 1,400 Native Americans, 743 blacks, 237 Asians, and 2,791 of other races. Any significant improvement in overall survival to hospital discharge was not linked with prehospital TBI guidelines. Patients with severe TBI had a double adjusted survival rate, and those with severe, incubated TBI had a triple adjusted survival rate. There was a significant association with guideline implementation and survival to hospital admission. Widespread implementation of the prehospital TBI treatment guidelines was supported by these guidelines.