[1] Emory Univ, Dept Emergency Med, Atlanta, GA 30322 USA
[2] Boston Med Ctr, Dept Emergency Med, Boston, MA USA
[3] Columbia Univ, Valegos Coll Phys & Surg, Dept Emergency Med, New York, NY USA
[4] Univ Med Ctr, Dept Emergency Med, El Paso, TX USA
[5] Case Western Reserve Univ, MetroHlth Med Ctr, Dept Emergency Med, Cleveland, OH USA
[6] Indiana Univ, Dept Emergency Med, Indianapolis, IN 46204 USA
[7] UNLV, Sch Med, Dept Emergency Med, Las Vegas, NV USA
[8] Univ Missouri, Sch Med, Dept Emergency Med, Columbia, MO USA
[9] UNTHSC TCU, Dept Emergency Med, Sch Med, Ft Worth, TX USA
[10] Baylor Coll Med, Dept Emergency Med, Dallas, TX USA
[11] Univ Pittsburgh, Sch Med, Dept Emergency Med, Pittsburgh, PA USA
[12] Eastern Virginia Med Sch, Sentara Norfolk Gen Hosp, Dept Emergency Med, Norfolk, VA USA
[13] UT SouthWestern Med Ctr, Dept Emergency Med, Dallas, TX USA