1. Centre for Evidence-Based Intervention, Department of Social Policy & Intervention, University of Oxford Barnett House, Oxford, UK
2. Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, Cape Town, South Africa
3. AIDS and Society Research Unit, Centre for Social Science Research, University of Cape Town, Cape Town, South Africa
4. Icahn School of Medicine at Mount Sinai, New York, USA