1. Health Systems Research Ethics Department, KEMRI-Wellcome Trust Research Programme , Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
2. Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford , Old Road, Oxford OX3 7BN, UK
3. Health Systems and Policy Division, School of Public Health and Family Medicine, University of Cape Town , Falmouth Road, Observatory, Cape Town 7925, South Africa
4. Department of Global Health and Development, London School of Hygiene and Tropical Medicine , Keppel Street, London WC1E 7HT, UK