1 Maternal, Newborn, Child and Adolescent Health and Ageing Department, World Health Organization, Geneva, Switzerland. Electronic address: gutholdr@who.int.
2 Division of Data, Analytics, Planning and Monitoring, Data and Analytics Section, UNICEF, New York, New York; Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden.
3 Adolescent Health Unit, Institute of Child Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
4 Global Adolescent Health Group, Burnet Institute, Melbourne, Victoria, Australia.
5 Maternal, Newborn, Child and Adolescent Health and Ageing Department, World Health Organization, Geneva, Switzerland.
6 Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
7 Department of Mental Health and Substance Use, World Health Organization, Geneva, Switzerland.
8 UN Major Group for Children and Youth, London, United Kingdom.
9 Independent Consultant, Tannay, Switzerland.
10 MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Glasgow, United Kingdom.
11 Technical Division, Sexual and Reproductive Health Branch, UNFPA, Geneva, Switzerland.
12 UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
13 Division of Data, Analytics, Planning and Monitoring, Data and Analytics Section, UNICEF, New York, New York.