1 Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response, School of Public Health and Primary Care, Prince of Wales Hospital, Sha tin, Hong Kong. Electronic address: emily.chan@cuhk.edu.hk.
2 Accident and Emergency Medicine Academic Unit, Prince of Wales Hospital, Sha tin, Hong Kong.
3 School of Public Health and Primary Care, Prince of Wales Hospital, Sha tin, Hong Kong.