1. Department of Emergency Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Republic of Korea
2. Department of Emergency Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
3. Department of Pediatrics, Soonchunhyang University Hospital, Seoul, Republic of Korea
4. Department of Emergency Medicine, Soonchunhyang University Gumi Hospital, Gumi, Republic of Korea
5. Department of Biostatistics, Clinical Trial Center, Soonchunhyang University Cheonan Hospital, Cheonan, Republic of Korea.