[1] Anhui Med Univ, Sch Publ Hlth, Dept Epidemiol & Biostat, Hefei, Anhui, Peoples R China
[2] Anhui Med Univ, Anhui Prov Lab Populat Hlth & Major Dis Screening, Hefei, Anhui, Peoples R China
[3] Chinese Univ Hong Kong, Jockey Club Sch Publ Hlth & Primary Care, Div Epidemiol, Hong Kong, Hong Kong, Peoples R China
[4] Fudan Univ, Zhongshan Hosp, Dept Gastroenterol, Shanghai 200433, Peoples R China
[5] Anhui Med Univ, Affiliated Hosp 1, Dept Gastroenterol, Hefei, Peoples R China
[6] Anhui Med Univ, Affiliated Hosp 2, Hefei, Anhui, Peoples R China
[7] Chinese Univ Hong Kong, Hong Kong Branch, Chinese Cochrane Ctr, Hong Kong, Hong Kong, Peoples R China