1 Department of Epidemiology and Medical Statistics, Institute of Advanced Medical Research and Training, College of Medicine, University of Ibadan, Nigeria.
2 Child Health Division, Ministry of Health, Kampala, Uganda.
3 Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso.
4 Department of Health Services Research, School for Public Health and Primary Care, Maastricht University, The Netherlands.
5 Centre for Applied Biostatistics, Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden.
6 UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, World Health Organization, Geneva, Switzerland.