[1] KEMRI Wellcome Trust Res Programme, Hlth Econ Res Unit, Nairobi, Kenya
[2] Univ Oxford, Ctr Trop Med & Global Hlth, Nuffield Dept Med, Oxford, England
[3] London Sch Hyg & Trop Med, Dept Epidemiol & Populat Hlth, London, England
[4] Univ Ghana, Sch Publ Hlth, Dept Hlth Policy Planning & Management, Legon, Accra, Ghana
[5] Africa Ctr Dis Control & Prevent, Hlth Econ & Financing Programme, Addis Ababa, Ethiopia