[1] Naval Med Univ Second Mil Med Univ, Changzheng Hosp, Dept Gastroenterol, 415 Fengyang Rd, Shanghai 200003, Peoples R China
[2] Fudan Univ, Zhongshan Hosp, Evidence Based Med Ctr, Shanghai 200032, Peoples R China
[3] Peking Univ Peoples Hosp, Dept Gastroenterol, 11 Xizhimen South St, Beijing 100044, Peoples R China
[4] Gen Hosp Northern Theater Command, Dept Gastroenterol, 83 Wenhua Rd, Shenyang 110015, Liaoning, Peoples R China
[5] Huazhong Univ Sci & Technol, Tongji Med Coll, Union Hosp, Dept Gastroenterol, 1277 Jiefang Ave, Wuhan 430022, Hubei, Peoples R China