[1] Univ Maryland, Sch Med, Dept Emergency Med, Baltimore, MD 21201 USA
[2] Temple Univ, Sch Med, Dept Emergency Med, Philadelphia, PA 19122 USA
[3] San Francisco Gen Hosp, Dept Emergency Med, San Francisco, CA 94110 USA
[4] Finch Univ, Chicago Med Sch, Dept Emergency Med, Chicago, IL USA
[5] Thomas Jefferson Univ, Jefferson Med Coll, Dept Emergency Med, Philadelphia, PA 19107 USA
[6] Wake Forest Univ, Bowman Gray Sch Med, Dept Emergency Med, Winston Salem, NC USA