[1] Khon Kaen Univ, Fac Med, Dept Emergency Med, Khon Kaen 40002, Thailand
[2] Princess Margaret Hosp, Accid & Emergency Dept, Kowloon, Lai Chi Kok, 2-10 Princess Margaret Hosp Rd, Hong Kong, Peoples R China
[3] Univ Hong Kong, Li Ka Shing Fac Med, Emergency Med Unit, Pokfulam, Hong Kong, Peoples R China
[4] Khon Kaen Univ, Fac Med, Dept Med, Khon Kaen 40002, Thailand