1. Centre de Recherche en Reproduction Humaine et en Démographie, CNHU/HKM, Avenue Jean-Paul II, Cotonou, Benin
2. Unit of Health Services Organization, Department of Public Health, Institute of Tropical Medicine, 155 Nationalestraat, 2000 Antwerp, Belgium
3. Health Policy Unit, Department of Public Health, Institute of Tropical Medicine, 155 Nationalestraat, 2000 Antwerp, Belgium
4. School of Public Health, University of the Western Cape, Robert Sobukwe Road, Bellville 7535, Republic of South Africa
5. Health Systems Unit, Department of Public Health, Institute of Tropical Medicine, 155 Nationalestraat, 2000 Antwerp, Belgium