[1] Peking Univ Third Hosp, Dept Urol, Beijing 100191, Peoples R China
[2] Peking Univ Third Hosp, Res Ctr Clin Epidemiol, Beijing 100191, Peoples R China
[3] Tongxin Peoples Hosp, Dept Urol, Tongxin 751300, Ningxia, Peoples R China
[4] Peking Univ Third Hosp, Dept Nephrol, Beijing 100191, Peoples R China