1. Department of Gastroenterology, Ajou University School of Medicine, Suwon 16499, Republic of Korea
2. Department of Biomedical Informatics, Ajou University School of Medicine, Suwon 16499, Republic of Korea
3. Office of Biostatistics, Ajou Research Institute for Innovative Medicine, Ajou University Medical Center, Suwon 16499, Republic of Korea