1. Department of Health Informatics, Niigata University of Health & Welfare, Niigata, Japan
2. Department of Medical Informatics & Statistics, Niigata University Graduate School of Medical & Dental Sciences, Niigata, Japan
3. Division of Digestive & General Surgery, Niigata University Graduate School of Medical & Dental Sciences, Niigata, Japan
4. Department of Medical Informatics, Niigata University Medical & Dental Hospital, Niigata, Japan