1. Department of Pediatrics, Children's Memorial Hospital, Chicago, Illinois; Departments of
2. Pediatrics and Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
3. Department of Pediatrics, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts
4. Biostatistics Research Center, Tufts-New England Medical Center, Boston, Massachusetts
5. Pediatric Research in Office Settings, Department of Research, American Academy of Pediatrics, Elk Grove Village, Illinois
6. Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont
7. Continuity Research Network, Ambulatory Pediatric Association, McLean, Virginia
8. Holyoke Pediatric Associates, Holyoke, Massachusetts
9. Children's Hospital, Wayne State School of Medicine, Detroit, Michigan
10. Cambridge Pediatrics, Waldorf, Maryland
11. Mary Ann and J. Milburn Smith Child Health Research, Children's Memorial Research Center, Chicago, Illinois