1. Department of Internal Medicine, Gachon University College of Medicine, Incheon, Republic of Korea
2. Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
3. Department of Internal Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea
4. Kyungpook National University Hospital, School of Medicine, Daegu, Republic of Korea
5. Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
6. Department of Internal Medicine, Yeungnam University Hospital, Daegu, Republic of Korea
7. Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, Republic of Korea
8. Department of Internal Medicine, Kyung Hee University Hospital, Seoul, Republic of Korea