1. Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore , Singapore 119228 , Singapore
2. Lee Kong Chian School of Medicine, Nanyang Technological University , Singapore 308232 , Singapore
3. Duke-NUS Medical School, National University of Singapore , Singapore 169857 , Singapore
4. Department of Endocrinology, Singapore General Hospital , Singapore 169608 , Singapore
5. Department of Surgical Intensive Care, Singapore General Hospital , Singapore 169608 , Singapore