1. Department of Geriatrics and National Clinical Research Center for Geriatrics West China Hospital of Sichuan University Chengdu Sichuan China
2. Department of Gastroenterology Jiangyou 903 Hospital Mianyang Sichuan China
3. Department of Palliative Medicine, West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu Sichuan Province China