[1] Northwestern Univ, Feinberg Sch Med, Ann & Robert H Lurie Childrens Hosp Chicago, Pediat, Chicago, IL 60611 USA
[2] Univ Florida, Coll Med, Jacksonville, FL USA
[3] Childrens Hosp San Antonio, Baylor Coll Med, San Antonio, TX USA
[4] Duke Univ, Sch Med, Populat Hlth Sci, Durham, NC USA
[5] Duke Clin Res Inst, Durham, NC USA
[6] Michigan State Univ, Helen DeVos Childrens Hosp, Coll Human Med, Grand Rapids, MI USA
[7] Univ Missouri, Kansas City Sch Med, Childrens Mercy Hosp, Kansas City, MO 64110 USA
[8] Connecticut Childrens, Hartford, CT USA
[9] Cincinnati Childrens Hosp Med Ctr, Div Biostat & Epidemiol, Pediat, Cincinnati, OH 45229 USA
[10] Univ Cincinnati, Coll Med, Pediat, Cincinnati, OH USA
[11] Cincinnati Childrens Hosp Med Ctr, Ctr Better Hlth & Nutr, Heart Inst, Cincinnati, OH 45229 USA
[12] Alamo City Hlth Kids & Families, San Antonio, TX USA