1. Saw Swee Hock School of Public Health, National University of Singapore (NUS), 12 Science Drive 2, #10-01, Singapore 117549, Singapore
2. Health Intervention and Technology Assessment Program (HITAP), Department of Health, Ministry of Public Health, 6th Floor, 6th Building, Tiwanon Road, Nonthaburi 11000, Thailand
3. Department of Management Science, University of Strathclyde, 16 Richmond Street, Glasgow G1 1XQ, UK
4. Department of Pharmacy, Faculty of Science, NUS, 18 Science Drive 4, Singapore 117559, Singapore