1. Department of Health Sciences and Health Policy; University of Lucerne; Lucerne Switzerland
2. Discipline of Paediatrics; School of Women's and Children's Health; UNSW Medicine; University of New South Wales; Sydney New South Wales Australia
3. Kids Cancer Centre; Sydney Children's Hospital; Sydney New South Wales Australia
4. Oslo Centre for Biostatistics and Epidemiology; Oslo University Hospital, and Institute of Basic Medical Sciences; University of Oslo; Oslo Norway
5. Departement Gesundheit und Soziales; Abteilung Gesundheit; Aarau Switzerland
6. Cancer Registry Zurich and Zug; Institute of Surgical Pathology; University Hospital Zurich; Zurich Switzerland
7. Epidemiology, Biostatistics and Prevention Institute; University Zurich; Zurich Switzerland
8. Institute of Social and Preventive Medicine; University of Bern; Bern Switzerland