[1] George Washington Univ, Sch Med & Hlth Sci, Childrens Natl Med Ctr, Childrens Res Inst,Div Emergency Med, Washington, DC 20010 USA
[2] George Washington Univ, Sch Med & Hlth Sci, Childrens Natl Med Ctr, Childrens Res Inst,Ctr Hlth Serv & Community Res, Washington, DC 20010 USA
[3] Albert Einstein Coll Med, Jacobi Med Ctr, Dept Pediat, Div Emergency Med, Bronx, NY 10467 USA