1. Department of Gastroenterology; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
2. Department of Biomedical Engineering; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
3. Department of Clinical Epidemiology and Biostatistics; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
4. Health Screening and Promotion Center; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
5. Department of Internal Medicine; University of Hallym College of Medicine; Hallym University Sacred Heart Hospital; Anyang Korea
6. Department of Medicine; Division of Gastroenterology and Hepatology; Augusta University; Augusta GA USA