1. CERPOP, UMR 1295 Toulouse University, Inserm, Paul Sabatier University Toulouse France
2. Childhood Disability Registry in Haute‐Garonne University Hospital of Toulouse Toulouse France
3. Clinical Epidemiology Unit University Hospital of Toulouse Toulouse France
4. European Commission Joint Research Centre Ispra Italy
5. Department of Pediatrics, Clinical Sciences Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
6. Department of Orthopaedics General Hospital of Syros Syros Greece
7. Child and Adolescent Medicine Aarhus University Hospital Aarhus Denmark
8. Norwich Medical School, University of East Anglia Norwich UK