1. Department of Family Medicine, Inje University Sanggye Paik Hospital, Seoul, Korea.
2. Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
3. Department of Pediatrics, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
4. Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
5. Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
6. Department of Pediatrics, Hangang Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
7. Center for Clinical Services, National Cancer Center, Goyang, Korea.