1. Department of Medicine, Division of Infectious Diseases, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
2. Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
3. Department of Medicine, Division of Gastroenterology, University of California San Francisco, San Francisco, California, USA
4. Department of Infectious Disease, Cleveland Clinic, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
5. Department of Medicine, Division of Gastrointestinal and Liver Diseases, University of Southern California, Los Angeles, California, USA
6. Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
7. Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Chicago, Chicago, Illinois, USA