1. Noguchi Memorial Institute for Medical Research, College of Health Sciences; University of Ghana; Accra Ghana
2. Department of Clinical Sciences; Liverpool School of Tropical Medicine; Liverpool UK
3. MRC International Statistics and Epidemiology Group; London School of Hygiene & Tropical Medicine; London UK
4. Medical Statistics Department; London School of Hygiene & Tropical Medicine; London UK
5. Department of International Public Health; Liverpool School of Tropical Medicine; Liverpool UK