1. The First Clinical Medical School, Southern Medical University, Guangzhou, China
2. The Second Clinical Medical School, Southern Medical University, Guangzhou, China
3. Department of Gastroenterology, Guangdong Provincial Geriatrics Institute, National Key Clinical Specialty, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
4. Department of Gastroenterology, Geriatric Center, National Regional Medical Center, Guangdong Provincial People's Hospital Ganzhou Hospital, Southern Medical University, Ganzhou, China