[1] Univ Michigan, Dept Emergency Med, 1500 E Med Ctr Dr, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Dept Family Med, Ann Arbor, MI 48109 USA
[3] Univ Calif Los Angeles, David Geffen Sch Med, Harbor UCLA Med Ctr, Dept Emergency Med,Los Angeles Biomed Res Inst, Torrance, CA USA
[4] Berry Consultants, Austin, TX USA
[5] Univ Michigan, Dept Neurol, Ann Arbor, MI USA