[1] Chinese Acad Med Sci, Peking Union Med Coll Hosp, Dept Nephrol, 1 Shuaifuyuan,Wangfujing St, Beijing 100730, Peoples R China
[2] Chinese Acad Med Sci, Sch Nursing, 33 Badachu Rd, Beijing 100144, Peoples R China
[3] Peking Union Med Coll, 33 Badachu Rd, Beijing 100144, Peoples R China
[4] Chinese Acad Med Sci, Inst Basic Med Sci, Dept Epidemiol & Biostat, Beijing, Peoples R China
[5] Peking Union Med Coll, Beijing, Peoples R China
[6] Johns Hopkins Univ, Sch Nursing, Baltimore, MD USA
[7] Massachusetts Gen Hosp, Div Nephrol, Boston, MA 02114 USA