1. Department of Hematology, Gansu Provincial Hospital, Lanzhou, Gansu 730000, P.R. China
2. Department of Clinical Medicine, Gansu University of Traditional Chinese Medicine, Lanzhou, Gansu 730000, P.R. China
3. Evidence‑Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu 730000, P.R. China
4. Department of Gastroenterology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
5. Department of Gastroenterology, The Second Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
6. Institute of Clinical Research and Evidence Based Medicine, Lanzhou University, Lanzhou, Gansu 730000, P.R. China