1. Department of Pediatrics, Emory University School of Medicine, and Children’s Healthcare of Atlanta, Atlanta, Georgia;
2. Statistics and Epidemiology Unit, RTI International, Research Triangle Park, North Carolina;
3. Department of Pediatrics, University of Iowa, Iowa City, Iowa;
4. Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
5. Department of Pediatrics, Wayne State University, Detroit, Michigan;
6. Department of Pediatrics, Women & Infants Hospital, Brown University, Providence, Rhode Island;
7. Statistics and Epidemiology Unit, RTI International, Rockville, Maryland;
8. Department of Pediatrics, Rainbow Babies & Children’s Hospital, Case Western Reserve University, Cleveland, Ohio;
9. Centers for Disease Control and Prevention, Atlanta, Georgia; and
10. Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland