1. Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
2. Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
3. Department of Biostatistics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
4. Department of Pediatrics, Yonsei University College of Medicine, Seoul, Republic of Korea