1. Population Policy and Practice Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
2. Clinical Epidemiology, Department of Medicine, Karolinska Institutet and Centre for Health Equity Studies, Stockholm, Sweden
3. Child Health Evaluative Sciences, Toronto, Ontario, Canada
4. ICES, Toronto, Ontario, Canada
5. Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, Victoria, Australia
6. Bristol Royal Hospital for Children, Bristol, UK
7. Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
8. Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
9. Information Services Department, Finnish Institute for Health and Welfare, Helsinki, Finland
10. Faculty of Sociology, Anthropology and Folkloristics, University of Iceland, Reykjavík, Iceland
11. Division of Paediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
12. Dalla Lana School of Public Health, Toronto, Ontario, Canada
13. Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada