1. Department of Psychiatry, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
2. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
3. Division of Pulmonology, Department of Internal Medicine, Kangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
4. Department of Internal Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea.
5. Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Republic of Korea.
6. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Republic of Korea.
7. Division of Pulmonology, Department of Internal Medicine, Institute of Chest Disease, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
8. Division of Pulmonology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
9. Department of Internal Medicine, Ajou University School of Medicine, Suwon, Republic of Korea.