[1] Tulane Univ, Sch Publ Hlth & Trop Med, Dept Epidemiol, New Orleans, LA USA
[2] Chinese Acad Med Sci, Cardiovasc Inst, Beijing 100730, Peoples R China
[3] Chinese Acad Med Sci, Fuwai Hosp, Beijing 100730, Peoples R China
[4] Peking Union Med Coll, Beijing 100021, Peoples R China
[5] Tulane Univ, Sch Med, Dept Med, New Orleans, LA 70112 USA
[6] Washington Univ, Sch Med, Div Biostat, St Louis, MO 63110 USA