[1] Beijing Hosp, Natl Ctr Gerontol, MOH Key Lab Geriatr, 1 Dahua Rd, Beijing 100730, Peoples R China
[2] Jiamusi Univ, Affiliated Hosp 1, Dept Resp, Jiamusi, Peoples R China
[3] Ningxia Med Coll, Sch Publ Hlth, Yinchuan, Peoples R China
[4] Guangxi Zhuang Autonormous Dist Jiangbin Hosp, Nanning, Peoples R China
[5] Beijing Geriatr Hosp, Beijing, Peoples R China
[6] China Dis Control & Prevent Ctr, Beijing, Peoples R China
[7] Peking Univ, Clin Coll 4, Beijing Jishuitan Hosp, Beijing, Peoples R China