1. Department of Pediatrics, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea.
3. Department of Occupational and Environmental Medicine, Dankook University College of Medicine, Cheonan, Korea.
4. Department of Health Administration and Management, Soonchunhyang University, Asan, Korea.
5. Department of Information and Statistics, Korea National Open University, Seoul, Korea.
6. Department of Pediatrics, Konkuk University School of Medicine, Seoul, Korea.
7. Department of Pediatrics, Hallym University College of Medicine, Anyang, Korea.
8. Department of Pediatrics, CHA University College of Medicine, Seongnam, Korea.
9. Department of Pediatrics, Inje University College of Medicine, Seoul, Korea.