1. Division of Gastroenterology and Hepatology Department of Internal Medicine Kangbuk Samsung Hospital Sungkyunkwan University School of Medicine Seoul South Korea
2. Center for Cohort Studies Total Healthcare Center Kangbuk Samsung Hospital School of Medicine Sungkyunkwan University Seoul South Korea
3. Department of Occupational and Environmental Medicine Kangbuk Samsung Hospital School of Medicine Sungkyunkwan University Seoul South Korea
4. Department of Clinical Research Design & Evaluation SAIHST Sungkyunkwan University Seoul South Korea
5. Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research Johns Hopkins University Bloomberg School of Public Health Baltimore MD USA
6. Department of Family Medicine Kangbuk Samsung Hospital Sungkyunkwan University School of Medicine Seoul South Korea