1. Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
2. Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
3. Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
4. The Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
5. Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA