[1] Duke Univ, Dept Pediat, DUMC Box 2739, Durham, NC 27710 USA
[2] RTI Int, Social Stat & Environm Sci Unit, Rockville, MD USA
[3] Emory Univ, Sch Med, Dept Pediat, Childrens Healthcare Atlanta, Atlanta, GA USA
[4] Nationwide Childrens Hosp, Dept Pediat, Columbus, OH USA
[5] Childrens Hosp Philadelphia, Dept Pediat, Philadelphia, PA 19104 USA
[6] Univ Penn, Philadelphia, PA 19104 USA
[7] Univ Iowa, Dept Pediat, Iowa City, IA 52242 USA
[8] Univ Chicago, Pritzker Sch Med, Chicago, IL 60637 USA
[9] Brown Univ, Alpert Med Sch, Providence, RI 02912 USA
[10] Women & Infants Hosp Rhode Isl, Providence, RI 02908 USA
[11] Case Western Reserve Univ, Rainbow Babies & Childrens Hosp, Cleveland, OH 44106 USA
[12] Univ Missouri, Sch Med, Childrens Mercy Hosp, Kansas City, MO 64108 USA
[13] Univ Hosp, Cincinnati Childrens Hosp Med Ctr, Cincinnati, OH USA
[14] Good Samaritan Hosp, Cincinnati, OH USA
[15] Duke Univ, Sch Med, Univ North Carolina, Univ Hosp, Durham, NC USA
[16] Duke Reg Hosp, Durham, NC USA
[17] Emory Univ, Childrens Healthcare Atlanta, Grady Mem Hosp, Atlanta, GA 30322 USA
[18] Emory Univ, Hosp Midtown, Atlanta, GA 30322 USA
[19] Eunice Kennedy Shriver Natl Inst Child Hlth & Hum, Rockville, MD USA
[20] Indiana Univ, Riley Hosp Children, Methodist Hosp, Univ Hosp, Indianapolis, IN 46204 USA
[21] Wishard Hlth Serv, Indianapolis, IN USA
[22] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Childrens Mem Hermann Hosp, Houston, TX 77030 USA
[23] Lyndon Baines Johnson Gen Hosp, Harris Cty Hosp Dist, Houston, TX USA
[24] Nationwide Childrens Hosp, Columbus, OH USA
[25] Ohio State Univ, Med Ctr, Columbus, OH 43210 USA
[26] RTI Int, Rockville, MD USA
[27] Stanford Univ, Dominican Hosp, El Camino Hosp, Mountain View, CA USA
[28] Lucile Packard Childrens Hosp, Mountain View, CA USA
[29] Tufts Med Ctr, Floating Hosp Children, Boston, MA 02111 USA
[30] Univ Alabama Birmingham Hlth Syst, Birmingham, AL USA
[31] Childrens Hosp Alabama, Birmingham, AL USA
[32] Univ Calif Los Angeles, Mattel Childrens Hosp, Santa Mon Hosp, Los Robles Hosp & Med Ctr, Los Angeles, CA USA
[33] Olive View Med Ctr, Los Angeles, CA USA
[34] Univ Calif San Diego, Med Ctr, 225 Dickinson St, San Diego, CA 92103 USA
[35] Sharp Mary Birch Hosp Women & Newborns, San Diego, CA USA
[36] Univ Iowa, Cedar Rapids, IA USA
[37] Mercy Med Ctr, Cedar Rapids, IA USA
[38] Univ Miami, Holtz Childrens Hosp, Miami, FL USA
[39] Univ New Mexico, Hlth Sci Ctr, Albuquerque, NM 87131 USA
[40] Univ Penn, Hosp Univ Penn, Penn Hosp, Philadelphia, PA 19104 USA
[41] Childrens Hosp Philadelphia, Philadelphia, PA 19104 USA
[42] Univ Rochester, Med Ctr, Golisano Childrens Hosp, Rochester, NY 14642 USA
[43] Univ Buffalo, Womens & Childrens Hosp Buffalo, Buffalo, NY USA
[44] Univ Texas Southwestern Med Ctr Dallas, Parkland Hlth & Hosp Syst, Dallas, TX 75390 USA
[45] Childrens Med Ctr Dallas, Dallas, TX USA
[46] Univ Utah, Med Ctr, Intermt Med Ctr, LDS Hosp, Salt Lake City, UT USA
[47] Primary Childrens Med Ctr, Salt Lake City, UT 84103 USA
[48] Wake Forest Univ, Baptist Med Ctr, Forsyth Med Ctr, Winston Salem, NC 27101 USA
[49] Brenner Childrens Hosp, Winston Salem, NC USA
[50] Wayne State Univ, Hutzel Womens Hosp, Detroit, MI USA