1. Department of Medicine, Indiana University School of Medicine, Indianapolis2Department of Medicine, Medical University of South Carolina, Charleston
2. Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
3. Methodist Dallas Medical Center, Dallas, Texas
4. Department of Medicine, Washington University in St Louis, St Louis, Missouri
5. Department of Medicine, Medical University of South Carolina, Charleston6Department of Medicine, University of Michigan, Ann Arbor
6. Department of Medicine, University of Michigan, Ann Arbor
7. Department of Medicine, Indiana University School of Medicine, Indianapolis
8. Department of Medicine, Medical University of South Carolina, Charleston
9. Royal Wolverhampton Trust, Wolverhampton, United Kingdom
10. Center for Endoscopic Research and Therapeutics, University of Chicago School of Medicine, Chicago, Illinois
11. Department of Biostatistics, Indiana University School of Medicine, Indianapolis