1. MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
2. School of Demography, The Australian National University, Canberra, Australia
3. CU Population Center, Institute of Behavioral Science, University of Colorado at Boulder, Boulder, Colorado, USA
4. Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden
5. School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
6. Center for Population Health Sciences, Hanoi University of Public Health, Ha Noi, Vietnam