1. Department of Psychology, Syracuse University, Syracuse, New York, USA;
2. Center for AIDS Prevention Studies, University of California, San Francisco, San Francisco, California, USA;
3. International Center for Research on Women, Washington, District of Columbia, USA;
4. Department of Social Statistics and Demography, University of Southampton, Southampton, UK;
5. Africa Health Research Institute, KwaZulu-Natal, South Africa;
6. Human Sciences Research Council, Sweetwaters, South Africa;
7. School of Clinical Medicine, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa;
8. Department of Health Behavior and Biological Sciences, Center for Sexuality and Health Disparities, School of Nursing, University of Michigan, Ann Arbor, Michigan, USA;
9. Academic Unit of Primary Care and Population Sciences and Department of Social Statistics and Demography, University of Southampton, Southampton, UK;
10. Africa Health Research Institute, School of Nursing & Public Health, University of KwaZulu-Natal, KwaZulu-Natal, South Africa;
11. Research Department of Epidemiology & Public Health, University College London, London, UK