1. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia2Division of Rheumatology, Nemours A.I. duPont Hospital for Children, Thomas Jefferson University, Wilmington, Delaware3Rutgers Biomed
2. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia4Division of Gastroenterology, Hospital of the University of Pennsylvania, Philadelphia
3. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia5Clinical Epidemiology, HealthCore, Wilmington, Delaware
4. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
5. Division of Rheumatology, Nemours A.I. duPont Hospital for Children, Thomas Jefferson University, Wilmington, Delaware
6. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia3Rutgers Biomedical and Health Sciences, Child Health Institute of New Jersey, New Brunswick