[1] Childrens Natl Med Ctr, Dept Emergency Med, Washington, DC 20010 USA
[2] George Washington Univ, Sch Med & Hlth Sci, Washington, DC 20052 USA
[3] George Washington Univ, Sch Med & Hlth Sci, Pediat & Emergency Med, Washington, DC 20052 USA
[4] Childrens Natl Med Ctr, Div Emergency Med, Qual, Washington, DC 20010 USA