1. Health Services Research Unit, Singapore General Hospital, Singapore 169608, Singapore
2. MOH Holdings Pte Ltd., 1 Maritime Square, Singapore 099253, Singapore
3. School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow G12 8QQ, UK
4. NUS Yong Loo Lin School of Medicine, Singapore 117597, Singapore
5. Department of Psychiatry, Singapore General Hospital, Singapore 169608, Singapore
6. SingHealth Duke-NUS Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore 169857, Singapore
7. Saw Swee Hock School of Public Health, National University of Singapore, Singapore 117549, Singapore