[1] New York Methodist Hosp, Dept Emergency Med, Brooklyn, NY 11215 USA
[2] Univ Cincinnati, Dept Emergency Med, Cincinnati, OH USA
[3] Henry Ford Hosp, Dept Emergency Med, Detroit, MI 48202 USA
[4] Univ Mississippi, Med Ctr, Dept Emergency Med, Jackson, MS 39216 USA
[5] Univ Michigan, Dept Emergency Med, Ann Arbor, MI 48109 USA
[6] Univ Calif Davis, Med Ctr, Dept Emergency Med, Sacramento, CA 95817 USA