[1] Univ Ulsan, Asan Med Ctr, Dept Internal Med, Coll Med,Div Pulmonol & Crit Care Med, Seoul, South Korea
[2] Univ Ulsan, Asan Med Ctr, Coll Med, Dept Clin Epidemiol & Biostat, Seoul, South Korea
[3] Keimyung Univ, Dongsan Med Ctr, Sch Med, Dept Internal Med, Daegu, South Korea
[4] Univ Ulsan, Asan Med Ctr, Dept Internal Med, Coll Med,Div Endocrinol & Metab, Seoul, South Korea
[5] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Infect Dis, Seoul, South Korea