1. NUS Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
2. Saw Swee Hock School of Public Health, National University of Singapore, Singapore 117549, Singapore
3. Health Services Research Unit, Singapore General Hospital, Singapore 169608, Singapore
4. SingHealth Duke-NUS Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore 169857, Singapore
5. Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore 169856, Singapore