1. Department of Internal Medicine, Inje University Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea.
3. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Division of Pulmonology and Allergy, Department of Internal Medicine, Regional Center for Respiratory Disease, Yeungnam University College of Medicine, Daegu, Korea.
5. Novartis Korea Ltd., Seoul, Korea.
6. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.