1. Division of Pulmonary, Allergy and Critical Care Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea.
2. Myeongmun Clinic of Internal Medicine, Yongin, Korea.
3. Joeun Clinic of Internal Medicine, Dangjin, Korea.
4. Neulpurun Clinic of Otolaryngology, Anyang, Korea.
5. Division of Pulmonary, Allergy and Critical Care Medicine, Konkuk University Hospital, Seoul, Korea.
6. Division of Pulmonary, Allergy and Critical Care Medicine, Kangnam Sacred Heart Hospital, Seoul, Korea.
7. Pyeongchon-Family Clinic of Internal Medicine, Anyang, Korea.
8. Division of Pulmonary, Allergy and Critical Care Medicine, Chuncheon Sacred Heart Hospital, Chuncheon, Korea.
9. Haengbok-Dream Clinic of Internal Medicine, Daegu, Korea.
10. Hanyang Clinic of Internal Medicine, Seoul, Korea.
11. Division of Pulmonary, Allergy and Critical Care Medicine, Kyung Hee University, Seoul, Korea.
12. Hongjunggon Clinic of Internal Medicine, Anyang, Korea.
13. Rapha Clinic of Otolaryngology, Anyang, Korea.
14. Chahyunggun Clinic of Otolaryngology, Anyang, Korea.
15. Leejaemyung Clinic of Internal Medicine, Anyang, Korea.
16. Seojungsan Clinic of Internal Medicine, Seoul, Korea.