1. MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
2. MRC/UVRI and LSHTM Uganda Research Unit, Entebbe P.O. Box 49, Uganda
3. Department of Clinical Research, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
4. The Health Research Unit Zimbabwe, Biomedical Research and Training Institute, Harare P.O. Box A178, Zimbabwe
5. Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre 312233, Malawi
6. Health Economics Policy Unit, Kamuzu University of Health Sciences, Blantyre 312225, Malawi
7. Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
8. Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 1QU, UK
9. SAMRC/Wits Developmental Pathways for Health Research Unit, School of Clinical Medicine, University of the Witwatersrand, Johannesburg 2050, South Africa
10. Department of Population Health, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK