1. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Pediatrics, School of Medicine, Kyungpook National University, Daegu, Korea
3. Crohn's and Colitis Association in Daegu-Gyeongbuk (CCAiD), Daegu, Korea
4. Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Seoul, Korea
5. Department of Pediatrics, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea