1. Department of Internal Medicine; Korea University College of Medicine; Seoul Korea
2. Department of Internal Medicine; Kyungpook National University School of Medicine; Daegu Korea
3. Department of Internal Medicine; Yonsei University Wonju College of Medicine; Wonju Korea
4. Department of Internal Medicine; Soonchunhyang University College of Medicine; Asan Korea
5. Department of Internal Medicine; Yonsei University College of Medicine; Seoul Korea
6. Department of Internal Medicine; Keimyung University College of Medicine; Daegu Korea
7. Department of Internal Medicine; Inje University College of Medicine; Pusan Korea
8. Department of Internal Medicine; Hallym University College of Medicine; Chuncheon Korea
9. Department of Internal Medicine; Cheju Halla General Hospital; Jeju Korea
10. Department of Internal Medicine; Hanyang University College of Medicine; Seoul Korea
11. Department of Internal Medicine; Wonkwang University College of Medicine; Iksan Korea
12. Department of Biostatistics; Korea University College of Medicine; Seoul Korea