1. Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
2. Department of Geriatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
3. Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
4. Department of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
5. Department of Gastroenterology, Qilu Hospital of Shandong University, Jinan 250012, China
6. Department of Gastroenterology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an 710003, China
7. Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
8. Department of Epidemiology and Statistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing 100005, China