1. Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea
2. Department of Internal Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea
3. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
4. Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea
5. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
6. Department of Internal Medicine, Seoul National University College of Medicine, Seongnam, Korea
7. Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea
8. Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea
9. Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea
10. Bundang Jesaeng Hospital, Seongnam, Korea
11. Department of Public Health, Wonkwang University Graduate School, Iksan, Korea
12. Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea