1. Department of Pediatrics, Duke University, Durham, North Carolina;
2. Department of Pediatrics, Emory University and Children's Healthcare of Atlanta, Atlanta, Georgia;
3. Statistics and Epidemiology Unit, RTI International, Research Triangle Park, North Carolina;
4. Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, Ohio;
5. Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
6. Statistics and Epidemiology Unit, RTI International, Rockville, Maryland;
7. Department of Pediatrics, Wayne State University, Detroit, Michigan;
8. Eunice Kennedy Shriver National Institute of Child Health and Human Development and
9. National Cancer Institute, National Institutes of Health, Bethesda, Maryland;
10. Department of Pediatrics, Women & Infants Hospital, Brown University, Providence, Rhode Island;
11. Department of Pediatrics, University of Alabama, Birmingham, Alabama;
12. Department of Pediatrics, University of Texas Medical School, Houston, Texas;
13. Department of Pediatrics, University of California, San Diego, California;
14. University of Miami Miller School of Medicine, Miami, Florida;
15. Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio;
16. Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut;
17. Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California;
18. Tufts Medical Center, Boston, Massachusetts;
19. University of Rochester School of Medicine and Dentistry, Rochester, New York;
20. Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana;
21. University of Iowa, Iowa City, Iowa;
22. Wake Forest University, Winston-Salem, North Carolina; and
23. University of New Mexico Health Science Center, Albuquerque, New Mexico