1. Center for Crohn’s and Colitis, Department of Gastroenterology, Kyung Hee University College of Medicine, Seoul, Republic of Korea;
2. Department of Biostatistics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea;
3. Department of Statistics Support, Medical Science Research Institute, Kyung Hee University Medical Center, Seoul, Republic of Korea;
4. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea