1. Emergency Medicine Department, National University Hospital, National University Health System, Singapore 119074, Singapore
2. Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
3. Acute & Emergency Care Centre, Khoo Teck Puat Hospital, National Healthcare Group, Singapore 768828, Singapore
4. Emergency Department, Ng Teng Fong General Hospital, National University Health System, Singapore 609606, Singapore
5. Emergency Department, Sengkang General Hospital, Singapore Health Services, Singapore 544886, Singapore