1. Department of Public Health Science, Graduate School of Public Health, Seoul National University, Seoul, Korea.
2. Gachon Institute of Pharmaceutical Science, College of Pharmacy, Gachon University, Incheon, Korea.
3. Department of Internal Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Konkuk University School of Medicine, Seoul, Korea.
4. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
5. College of Medicine, Inha University, Incheon, Korea.