[1] Childrens Natl Hosp, Div Hematol, Washington, DC USA
[2] Childrens Natl Hosp, Div Oncol, Washington, DC USA
[3] George Washington Univ, Sch Med & Hlth Sci, Dept Pediat, Washington, DC 20052 USA
[4] George Washington Univ, Sch Med & Hlth Sci, Dept Psychiat, Washington, DC 20052 USA
[5] George Washington Univ, Sch Med & Hlth Sci, Dept Behav Sci, Washington, DC 20052 USA