[1] Korea Univ, Ansan Hosp, Dept Emergency Med, Ansan, Gyeonggi Do, South Korea
[2] Inje Univ, Dept Emergency Med, Ilsanpa Hosp, Goyang Si, Gyeonggi Do, South Korea
[3] Natl Emergency Med Ctr, EMS Informat & Planning Team, Seoul, South Korea
[4] Seoul Natl Univ, Biomed Res Inst, Dept Emergency Med, 101 Daehak Ro, Seoul 110744, South Korea
[5] Seoul Natl Univ, Coll Med, Dept Emergency Med, Seoul, South Korea