1. aDepartment of Pediatrics, Southern California Permanente Medical Group, San Diego, California
2. bDepartment of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of California, San Diego School of Medicine, San Diego, California
3. cDepartment of Gastroenterology, Rady Children’s Hospital, San Diego, California
4. dDepartment of Pediatrics, Kaiser Permanente South Bay Medical Center, Southern California Permanente Medical Group, Manhattan Beach, California
5. eDepartment of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California
6. fAmherst College, Amherst, Massachusetts