[1] Northwestern Univ, Feinberg Sch Med, Dept Pediat, Ann & Robert H Lurie Childrens Hosp Chicago, Chicago, IL 60611 USA
[2] Childrens Hosp Neonatal Consortium, Kansas City, MO USA
[3] Univ Missouri, Kansas City Sch Med, Dept Pediat, Childrens Mercy Hosp & Clin, Kansas City, MO 64110 USA
[4] Univ Penn, Perelman Sch Med, Dept Pediat, Childrens Hosp Philadelphia, Philadelphia, PA 19104 USA
[5] Emory Univ, Sch Med, Dept Pediat, Childrens Healthcare Atlanta Egleston, Atlanta, GA USA
[6] Ohio State Univ, Coll Med, Nationwide Childrens Hosp, Dept Pediat, Columbus, OH 43210 USA
[7] Univ Colorado, Childrens Hosp Colorado, Sch Med, Aurora, CO USA
[8] Univ Pittsburgh, Sch Med, Dept Pediat, Childrens Hosp Pittsburgh, Pittsburgh, PA 15261 USA
[9] Cook Childrens Hosp, Ft Worth, TX USA
[10] Univ Cincinnati, Cincinnati Childrens Hosp Med Ctr, Sch Med, Cincinnati, OH USA
[11] Univ Washington, Seattle Childrens Hosp, Seattle, WA 98195 USA
[12] Childrens Hosp Assoc Inc, Overland Pk, KS USA