[Cao, Jing] Univ South China, Affiliated Changsha Cent Hosp, Hengyang Med Sch, Med Insurance Dept, Changsha 410004, Hunan, Peoples R China.
[Su, Yingjie] Univ South China, Affiliated Changsha Cent Hosp, Hengyang Med Sch, Dept Emergency Med, Changsha 410004, Hunan, Peoples R China.
[Zhao, Sue; Yang, HZ; Yang, Hongzhong; Xiao, Yijia] Univ South China, Affiliated Changsha Cent Hosp, Hengyang Med Sch, Dept Resp & Crit Care Med, Changsha 410004, Hunan, Peoples R China.