Injured patients (n= 476).
Prehospital tranexamic acid (TXA) within 1 hour from time of injury (Early group, n= 238).
Prehospital TXA beyond 1 hour (Delayed group, n= 238).
Patients from both groups had similar demographics, injury characteristics and shock severity but those in the delayed group had greater prehospital resuscitation requirements and longer prehospital times. Stratified Kaplan-Meier analysis demonstrated significant separation for those in the early group (log-rank chi-square test, 4.99) with no separation for patients in the delayed group (log-rank chi-square test, 0.04). Stratified Cox Hazard regression verified, after controlling for confounders, that early TXA was associated with a 65% lower independent hazard for 30-day mortality (HR 0.35) with no independent survival benefit found in delayed patients (HR 1.00). Early TXA patients had lower incidence of multiple organ failure and 6-hour and 24-hour transfusion requirements.