1. Hanoi University of Public Health , 1A Duc Thang, Bac Tu Liem, Ha Noi 10000, Vietnam
2. Global Health and Development, London School of Hygiene and Tropical Medicine , Keppel St, London WC1E 7HT, United Kingdom
3. School of Sociology and Social Policy, University of Leeds , Leeds LS2 9JT, United Kingdom
4. Nossal Institute for Global Health Melbourne School of Population and Global Health, The University of Melbourne , Victoria 3010, Australia