[1] Childrens Hosp, Div Emergency Med, Boston, MA 02115 USA
[2] Childrens Hosp, Program Clin Effectiveness, Boston, MA 02115 USA
[3] Childrens Hosp, Child Dev Unit, Boston, MA 02115 USA
[4] Brigham & Womens Hosp, Dept Qual Measurement & Improvement, Boston, MA 02115 USA
[5] Harvard Univ, Sch Med, Boston, MA USA