[1] Univ Arizona, Coll Med, Dept Emergency Med, Tucson, AZ 85724 USA
[2] Washington Univ, Sch Med St Louis, St Louis, MO USA
[3] McMaster Univ, Div Emergency Med, Hamilton, ON, Canada
[4] Loma Linda Univ, Dept Med, Dept Emergency Med, Div Pulm & Crit Care Med, Loma Linda, CA 92350 USA
[5] McMaster Univ, Michael G DeGroote Sch Med, Hamilton, ON, Canada