[1] Sunnybrook & Womens Coll Hlth Sci Ctr, Prehosp & Transport Med Res Program, Toronto, ON M4N 3M5, Canada
[2] Univ Washington, Harborview Med Ctr, Seattle, WA 98104 USA
[3] Univ British Columbia, British Columbia Ambulance Serv, Vancouver, BC V5Z 1M9, Canada
[4] Univ Pittsburgh, Dept Emergency Med, Pittsburgh, PA USA
[5] Univ Alabama, Dept Emergency Med, Birmingham, AL USA
[6] Med Coll Wisconsin, Dept Emergency Med, Milwaukee, WI 53226 USA
[7] Univ Iowa Childrens Hosp, Univ Iowa Carver Coll Med, Iowa City, IA USA
[8] UC San Diego, Dept Emergency Med, San Diego, CA USA
[9] Univ Texas SW Med Ctr Dallas, Dept Surg, Dallas, TX 75390 USA
[10] Oregon Hlth & Sci Univ, Dept Emergency Med, Ctr Policy & Res Emergency Med, Portland, OR 97201 USA