[1] Sichuan Univ, West China Hosp, Dept Resp Med & Crit Care Med, Chengdu 610041, Peoples R China
[2] Guizhou Prov Peoples Hosp, Inst Resp Dis, Dept Resp Med & Crit Care Med, Guiyang 550002, Peoples R China
[3] Xinjiang Med Univ, Affiliated Hosp 2, Dept Resp Med, Urumqi 830063, Xinjiang, Peoples R China
[4] Guizhou Prov Peoples Hosp, Sch Nursing, Guiyang 550001, Peoples R China