1. Department of Preventive Medicine Yonsei University College of Medicine Seoul Republic of Korea
2. Department of Internal Medicine Yonsei University College of Medicine Seoul Republic of Korea
3. Institute of Gastroenterology Yonsei University College of Medicine Seoul Republic of Korea
4. Yonsei Liver Centre, Severance Hospital Yonsei University Health System Seoul South Korea
5. Department of Public Health, Graduate School Yonsei University College of Medicine Seoul South Korea
6. The Institute for Occupational Health Yonsei University College of Medicine Seoul South Korea