Department of Surgery, Oregon Health & Science University, Portland. Department of Surgery, Duke University School of Medicine, Durham, North Carolina. Department of Biostatistics, University of Washington, Seattle. Department of Surgery, University of Washington, Seattle. Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas. Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas. Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Providence Health Care Research Institute, Vancouver, British Columbia, Canada. Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada. Division of Emergency Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada. Department of Emergency Medicine, Regions Hospital, St Paul, Minnesota. Department of Surgery, University of Alabama, Birmingham. Department of Surgery, University of Arizona, Phoenix. Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee. Department of Surgery, University of Cincinnati, Cincinnati, Ohio. Department of Surgery, McGovern Medical School, University of Texas Health Science Center, Houston. Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada. Department of Emergency Medicine, University of Cincinnati, Cincinnati, Ohio. Department of Surgery, Regions Hospital, St Paul, Minnesota. Trauma Surgery, Texas Health Presbyterian Hospital, Dallas. Department of Emergency Medicine, John Peter Smith Health Network, Ft Worth, Texas. Johns Hopkins School of Medicine, Baltimore, Maryland. British Columbia Emergency Health Services, Vancouver, British Columbia, Canada. Department of Emergency Medicine, Baylor University Medical Center, Dallas, Texas. Department of Surgery, Mayo Clinic, Rochester, Minnesota. Department of Surgery, John Peter Smith Health Network, Ft Worth, Texas. Department of Emergency Medicine, Oregon Health & Science University, Portland, Oregon. Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, Minnesota. Department of Surgery, St Michael's Hospital, Toronto, Ontario, Canada. Department of Emergency Medicine, Medical City Plano, Plano, Texas. Emergency Medicine, Methodist Dallas Medical Center, Dallas, Texas. National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland. Trauma Surgery, Texas Health Harris Methodist Hospital, Ft Worth.