1. Department of Gastroenterology, Longgang district People’s Hospital, Shenzhen, Guangdong Province, China;
2. Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China;
3. Department of Gastroenterology, Wuxi City People’s Hospital Affiliated to Nanjing Medical University, Wuxi, China;
4. Department of Gastroenterology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China;
5. Department of Gastroenterology, Mianyang Central Hospital, Mianyang, China;
6. Department of Gastroenterology, Longgang Central Hospital, Shenzhen, China;
7. Department of Biostatistics, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China