1. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Gachon University School of Medicine, Incheon, Korea.
3. Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
4. Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
5. Department of Internal Medicine, Kangwon National University College of Medicine, Chuncheon, Korea.
6. Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
7. Department of Internal Medicine, Wonkwang University College of Medicine, Iksan, Korea.