[1] Univ Calif San Francisco, Dept Emergency Med, San Francisco, CA USA
[2] Lundquist Inst Biomed Innovat Harbor UCLA, Torrance, CA USA
[3] David Geffen Sch Med UCLA, Los Angeles, CA USA
[4] Harbor UCLA Med Ctr, Dept Emergency Med, Torrance, CA USA
[5] Brown Univ, Rhode Isl Hosp, Dept Emergency Med, Warren Alpert Med Sch, Providence, RI USA
[6] Ann & Robert H Lurie Childrens Hosp Chicago, Div Emergency Med, Chicago, IL USA
[7] Northwestern Univ, Feinberg Sch Med, Chicago, IL USA
[8] Boston Childrens Hosp, Div Emergency Med, Boston, MA USA
[9] Harvard Med Sch, Dept Emergency Med, Boston, MA USA
[10] Harvard Med Sch, Dept Pediat, Boston, MA USA
[11] Univ Calif San Francisco, Dept Emergency Med, 550 16th St,Box 0649, San Francisco, CA 94143 USA