National University of Singapore (NUS) - Yong Loo Lin School of Medicine, National University of Singapore (NUS) - Duke-NUS Medical School, National University of Singapore (NUS) - Duke-NUS Medical School, National University of Singapore (NUS) - Duke-NUS Medical School, National University of Singapore (NUS) - Duke-NUS Medical School, Tan Tock Seng Hospital - Department of Preventive and Population Medicine, National University of Singapore (NUS) - Department of Emergency Medicine, Khoo Teck Puat Hospital - Department of Acute and Emergency Care, National University of Singapore (NUS) - Emergency Medicine Department, Changi General Hospital - Accident & Emergency, Tan Tock Seng Hospital - Emergency Department, KK Women’s and Children’s Hospital, Singapore Armed Force Medical Corps, National University of Singapore (NUS) - Singapore General Hospital and National University of Singapore (NUS) - Health Services and Systems Research