[1] China Japan Friendship Hosp, Dept Clin Res & Data Management, Beijing, Peoples R China
[2] Natl Ctr Resp Dis, Beijing, Peoples R China
[3] Natl Clin Res Ctr Resp Dis, Beijing, Peoples R China
[4] Chinses Acad Med Sci, Inst Resp Med, Beijing, Peoples R China
[5] Capital Med Univ, Beijing Anzhen Hosp, Dept Resp & Crit Care Med, Beijing, Peoples R China
[6] Lanzhou Univ, Sch Publ Hlth, Lanzhou, Peoples R China
[7] China Japan Friendship Hosp, Dept Resp & Crit Care Med, Beijing, Peoples R China