1. Department of Paediatric Surgery and OrthopaedicsUniversity of Turku and Turku University Hospital Turku Finland
2. Department of Paediatric SurgeryKuopio University Hospital Kuopio Finland
3. Information Services DepartmentFinnish Institute for Health and Welfare Helsinki Finland
4. Department of BiostatisticsUniversity of Turku and Turku University Hospital Turku Finland
5. Department of PaediatricsKuopio University Hospital Kuopio Finland
6. Department of NeurobiologyCare Sciences and Society, Karolinska Institute Stockholm Sweden
7. Department of Paediatric SurgeryTampere University Hospital and Tampere University Tampere Finland