[1] Allegheny Hlth Network, Dept Emergency Med, Pittsburgh, PA USA
[2] Temple Univ Hosp & Med Sch, Dept Emergency Med, Philadelphia, PA 19140 USA
[3] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Dept Emergency Med, Boston, MA USA
[4] SUNY Buffalo, Dept Emergency Med, Buffalo Gen Med Ctr, Buffalo, NY 14260 USA
[5] Univ New Mexico, Hlth Sci Ctr, Dept Emergency Med, Albuquerque, NM 87131 USA
[6] Truman Med Ctr Hosp, Dept Emergency Med, Kansas City, MO USA