1 Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
2 Gastroenterology Division and Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, Philadelphia, Pennsylvania.
3 Gastroenterology Division, Perelman School of Medicine, Philadelphia, Pennsylvania.
4 Gastroenterology Division, Perelman School of Medicine and Center for Endoscopic Innovation, Research and Training, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.