[1] Vanderbilt Univ, Sch Med, Dept Med, Div Epidemiol, Nashville, TN 37203 USA
[2] Third Mil Med Univ, Coll Prevent Med, Dept Epidemiol, Chongqing, Peoples R China
[3] Shanghai Municipal Ctr Dis Control & Prevent, Shanghai, Peoples R China
[4] Shanghai Canc Inst, Dept Epidemiol, Shanghai, Peoples R China