[1] Xi An Jiao Tong Univ, Sch Publ Hlth, Hlth Sci Ctr, Dept Epidemiol & Hlth Stat, Xian 710061, Peoples R China
[2] Univ Liverpool Liverpool Sch Trop Med, Dept Clin Sci, Trop Clin Trials Unit, Liverpool L3 5QA, Merseyside, England
[3] Jiangsu Prov Hosp Integrat Chinese & Western Med, Dept Hlth Educ, Nanjing, Jiangsu, Peoples R China
[4] Peking Union Med Coll, Med Res & Biometr Ctr, Fuwai Hosp, Natl Ctr Cardiovasc Dis, Beijing, Peoples R China
[5] Chinese Acad Med Sci, Beijing, Peoples R China
[6] Keele Univ, Arthrit Res UK Primary Care Ctr, Res Inst Primary Care & Hlth Sci, Keele, Staffs, England
[7] Imperial Coll London, Sch Publ Hlth, Imperial Clin Trials Unit, London, England