1. Public Healthcare Center, Seoul National University Hospital, Seoul, Korea.
2. Department of Human Systems Medicine, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Emergency Medicine, Seoul National University College of Medicine and Hospital, Seoul, Korea.
4. National Emergency Medical Center, National Medical Center, Seoul, Korea.
5. Department of Emergency Medicine, Chosun University Hospital, Gwangju, Korea.
6. Department of Emergency Medicine, Chonnam National University Hospital, Gwangju, Korea.