[1] George Washington Univ, Dept Pediat, Div Crit Care Med, Washington, DC 20052 USA
[2] Childrens Natl Hosp, Pediat Eth Program, Washington, DC USA
[3] Childrens Hosp Philadelphia, Roberts Ctr Pediat Res, Dept Med Eth, 2716 South St, Philadelphia, PA 19146 USA
[4] Univ Penn, Perelman Sch Med, Dept Biostat, Pediat, Philadelphia, PA 19104 USA
[5] Univ Penn, Perelman Sch Med, Dept Pediat Med Eth & Hlth Policy, Philadelphia, PA 19104 USA