[1] Inje Univ, Coll Med, Seoul Paik Hosp, Dept Emergency Med, Seoul, South Korea
[2] Inha Univ, Sch Med, Dept Social & Prevent Med, Inchon, South Korea
[3] Seoul Natl Univ Hosp, Biomed Res Inst, Seoul 110744, South Korea
[4] Jeju Natl Univ, Sch Med, Dept Emergency Med, Cheju, South Korea
[5] Gyeongsang Natl Univ Hosp, Dept Emergency Med, Jinju, South Korea
[6] Seoul Natl Univ, Grad Sch Publ Hlth, Dept Epidemiol, Seoul, South Korea
[7] Seoul Natl Univ, Coll Med, Boramae Med Ctr, Dept Emergency Med, Seoul, South Korea