[1] Northwestern Univ, Feinberg Sch Med, Dept Pediat Emergency Med, Chicago, IL 60611 USA
[2] Northwestern Univ, Feinberg Sch Med, Dept Med Educ, Chicago, IL 60611 USA
[3] Univ Pittsburgh, Sch Med, Dept Pediat, Pittsburgh, PA 15261 USA
[4] UPMC Childrens Hosp Pittsburgh, Pittsburgh, PA USA
[5] Univ Pittsburgh, Sch Med, Dept Crit Care Med, Pittsburgh, PA 15261 USA
[6] Univ Pittsburgh, Sch Med, Safar Ctr Resuscitat Res, Pittsburgh, PA USA
[7] UPMC Childrens Hosp Pittsburgh, Hlth Informat Clin Effectiveness, Pittsburgh, PA USA