1. Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
2. Centre for Evidence-based Health Care, Division of Epidemiology and Biostatistics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
3. Department of Pharmacy, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
4. Honorary Research Fellow, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK