[1] Univ Missouri, Sch Med, Dept Emergency Med, DC029-10, Columbia, MO 65212 USA
[2] Boston Univ, Chobanian & Avedisian Sch Med, Dept Emergency Med, Boston, MA USA
[3] Boston Med Ctr, Dept Emergency Med, Boston, MA USA
[4] Southeast Hlth, Dept Emergency Med, Dothan, AL USA
[5] Ohio State Univ, Dept Emergency Med, Columbus, OH USA
[6] Univ Wisconsin, Sch Med & Publ Hlth, BerbeeWalsh Dept Emergency Med, Madison, WI USA
[7] Georgetown Univ, Sch Med, Dept Emergency Med, Washington, DC USA