1. Department of Clinical Sciences, Unit of Paediatrics Umeå University Umeå Sweden
2. Department of Public Health and Clinical Medicine, Unit of Research, Education and Development, Östersund Hospital Umeå University Umeå Sweden
3. Department of Clinical Sciences, Unit of Child and Adolescent Psychiatry Umeå University Umeå Sweden
4. Department of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm Sweden