1. Division of Research, Kaiser Permanente Northern California, Oakland, California.
2. Division of Endocrinology, Department of Medicine, Kaiser Permanente Oakland Medical Center, Oakland, California.
3. Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.
4. Department of Health Studies, Westat, Rockville, Maryland.
5. Department of Inpatient Pediatrics, Kaiser Permanente Oakland Medical Center, Oakland, California.