[1] Mayo Clin, Coll Med & Sci, Dept Emergency Med, 200 First St SW, Rochester, MN 55905 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Harbor UCLA Med Ctr, Dept Emergency Med, 924 Westwood Blvd 300, Los Angeles, CA 90024 USA
[3] Hennepin Cty Med Ctr, Dept Emergency Med, 730 S 8th St, Minneapolis, MN 55415 USA
[4] Harvard Med Sch, Brigham & Womens Hosp, Dept Emergency Med, 75 Francis St, Boston, MA 02215 USA