1. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, Korea.
3. Department of Health Administration and Management, College of Medical Science, Soonchunhyang University, Asan, Korea.
4. Department of Pediatrics, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
5. Department of Pediatrics, Inje University College of Medicine, Seoul, Korea.
6. Department of Occupational and Environmental Medicine, College of Medicine, Dankook University, Cheonan, Korea.
7. Department of Pediatrics, Konkuk University Hospital, Konkuk University School of Medicine, Seoul, Korea.
8. Department of Pediatrics, CHA University School of Medicine, Seongnam, Korea.
9. Department of Information and Statistics, Korea National Open University, Seoul, Korea.
10. Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea.
11. Department of Pediatrics, Dong-A University College of Medicine, Busan, Korea.
12. Department of Preventive Medicine, College of Medicine, Cheju National University, Jeju, Korea.