[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Emergency Med, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea
[2] Hanyang Univ, Coll Med, Dept Emergency Med, 222 Wangsimni Ro, Seoul 133791, South Korea
[3] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Clin Epidemiol & Biostat, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea
[4] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Pulm & Crit Med, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea
[5] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Lab Med, 88 Olymp Ro 43 Gil, Seoul 05505, South Korea