Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China. Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China. Center of Evidence-Based Medicine, Fudan University, Shanghai, China. Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China. Department of Interventional Radiotherapy, Zhongshan Hospital Fudan University, Shanghai, China. Department of Geratology, Zhongshan Hospital Fudan University, Shanghai, China. Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China.