8 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. dmslsg@nccs.com.sg.
9 Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
10 Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.