1. Division of Gastroenterology, Aichi Medical University School of Medicine, Yazakokarimata, Nagakute, Aichi, Japan
2. Division of General Medicine, Aichi Medical University School of Medicine, Yazakokarimata, Nagakute, Aichi, Japan
3. Division of Biostatistics, Clinical Research Center, Aichi Medical University School of Medicine, Yazakokarimata, Nagakute, Aichi, Japan