1. Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
3. Department of Internal Medicine, Guro Hospital, Korea University Medical Center, Seoul, Korea.
4. Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
5. Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
6. Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
9. Department of Internal Medicine, Asan Medical Center, Ulsan University College of Medicine, Seoul, Korea.
10. Department of Internal Medicine, Ulsan Medical Center, Ulsan University College of Medicine, Ulsan, Korea.
11. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
12. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
13. Department of Internal Medicine, College of Medicine, Inje University, Busan, Korea.
14. Department of Internal Medicine, College of Medicine, Inha University, Incheon, Korea.
15. Department of Internal Medicine, College of Medicine, Hallym University, Seoul, Korea.