1. Department of Social Policy and Intervention, University of Oxford, Oxford, UK
2. Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
3. Iranian Research Center for HIV/AIDS, Tehran University of Medical Sciences, Tehran, Iran
4. School of Social and Political Sciences, University of Edinburgh, Edinburgh, UK
5. OPTENTIA, Faculty of Health Sciences, North-West University, Vanderbijlpark, South Africa
6. School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
7. Department of Global Health, Boston University School of Public Health, Boston, MA, USA
8. Center for Global Health at Massachusetts General Hospital, Boston, MA, USA