[1] Univ Washington, Dept Pediat, Div Emergency Med, Seattle, WA USA
[2] Seattle Childrens Hosp, Emergency Dept, Seattle, WA USA
[3] Seattle Childrens Hosp, Ctr Divers & Hlth Equ, Seattle, WA USA
[4] Seattle Childrens Res Inst, Biostat Epidemiol & Analyt Res, Seattle, WA USA
[5] Seattle Childrens Res Inst, Ctr Child Hlth Behav & Dev, Seattle, WA USA
[6] Univ Washington, Sch Med, Dept Pediat, Div Gen Pediat, Seattle, WA USA
[7] Seattle Childrens Hosp, POB 5371,MB 7520, Seattle, WA 98145 USA