[1] Univ Ulsan, Dept Pulm & Crit Care Med, Asan Med Ctr, Coll Med, Seoul, South Korea
[2] Hallym Univ, Div Pulm Allergy & Crit Care Med, Dept Internal Med, Kangdong Sacred Heart Hosp, Ulsan, South Korea
[3] Ewha Womans Univ, Div Pulm & Crit Care Med, Dept Internal Med, Coll Med, Seoul, South Korea
[4] Univ Ulsan, Ulsan Univ Hosp, Dept Internal Med, Coll Med, Seoul, South Korea
[5] Sungkyunkwan Univ, Div Pulm & Crit Care Med, Dept Med, Samsung Med Ctr,Sch Med, Seoul, South Korea
[6] Yonsei Univ, Severance Hosp, Div Pulm & Crit Care Med, Dept Internal Med,Coll Med, Seoul, South Korea
[7] Catholic Univ Korea, Seoul St Marys Hosp, Div Pulm & Crit Care Med, Dept Internal Med,Coll Med, Seoul, South Korea
[8] Seoul Natl Univ, Dept Internal Med, SMG SNU Boramae Med Ctr, Coll Med, Seoul, South Korea
[9] Konkuk Univ, Div Pulm Allergy & Crit Care Med, Dept Internal Med, Sch Med, Seoul, South Korea
[10] Hallym Univ, Div Pulm Allergy & Crit Care Med, Dept Internal Med, Sacred Heart Hosp, Anyang, South Korea
[11] Sungkyunkwan Univ, Kangbuk Samsung Hosp, Dept Med, Sch Med, Seoul, South Korea