1. Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
2. Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
3. Department of Maternal, Newborn, Child and Adolescent Health, World Health Organization, Geneva, Switzerland
4. Division of Data, Analytics, Planning & Monitoring, United Nations Children’s Fund, New York, USA
5. UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland