1. Gastroenterological Center; Yokohama City University Medical Center; Yokohama Japan
2. Hepatobiliary and Pancreatic Medical Oncology; Kanagawa Cancer Center Hospital; Yokohama Japan
3. Gastroenterology Division of Internal Medicine; Kitasato University East Hospital; Sagamihara Japan
4. Division of Gastroenterology and Hepatology; Department of Internal Medicine; St Marianna University School of Medicine; Kawasaki Japan
5. Departments of Biostatistics and Epidemiology; Yokohama City University Graduate School of Medicine; Yokohama Japan
6. Clinical Research Coordinating Center; Yokohama City University Medical Center; Yokohama Japan
7. Gastroenterology; Yokohama City University Graduate School of Medicine; Yokohama Japan