[1] Hallym Univ Coll Med, Kangdong Sacred Heart Hosp, Dept Pulm Med, Seoul, South Korea
[2] Hallym Univ Coll Med, Kangdong Sacred Heart Hosp, Dept Crit Care Med, Seoul, South Korea
[3] Konkuk Univ Sch Med, Dept Internal Med, Konkuk, South Korea
[4] Catholic Univ Korea, Seoul St Marys Hosp, Dept Internal Med, Seoul, South Korea
[5] Catholic Univ Korea, Yeouido St Marys Hosp, Dept Internal Med, Seoul, South Korea
[6] Yonsei Univ Coll Med, Dept Internal Med, Seoul, South Korea
[7] Univ Ulsan Coll Med, Dept Pulm & Crit Care Med, Asan Med Ctr, Seoul, South Korea
[8] Ewha Womans Univ, Sch Med, Dept Internal Med, Seoul, South Korea
[9] Natl Strateg Coordinating Ctr Clin Res, Dept Clin Res Support, Seoul, South Korea
[10] Chosun Univ, Dept Nursing, Coll Med, Kwangju, South Korea