Selection of Participants
trauma
BLOOD
All patients (N = 680) were included who were recruited from one of 12 North American Level I trauma centers and met the following inclusion criteria: experienced severe injury requiring the highest level of trauma activation based on local criteria; received at least one unit of any blood component prior to hospital arrival or within one hour of admission; were predicted to require massive transfusion based on an Assessment of Blood Consumption score of two or greater, or by physician judgment of the need for massive transfusion (10 or more units of packed red blood cells in a 24-hour period); estimated age of 15 or older or weight of 50kg or greater if age unknown; and received directly from the scene of injury.