1. Accident and Emergency Department, Tuen Mun Hospital, Tuen Mun, Hong Kong
2. Accident and Emergency Department, Pok Oi Hospital, Yuen Long, Hong Kong
3. Accident and Emergency Department, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
4. Accident and Emergency Department, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
5. Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong