1. Division of Cancer Epidemiology and Biostatistics National Cancer Institute National Institutes of Health Rockville MD USA
2. Department of Global Public Health and Primary Care University of Bergen BergenNorway
3. Cancer Registry of Norway Oslo Norway
4. Information Services Department National Institute for Health and Welfare (THL) Helsinki Finland
5. Department of Neurobiology, Care Sciences and Society Division of Family Medicine Karolinska Institute Stockholm Sweden
6. Department of Clinical Epidemiology Aarhus University Hospital Aarhus Denmark
7. Department of Immunology, Genetics and Pathology Uppsala University UppsalaSweden
8. Department of Medicine Clinical Epidemiology Unit Karolinska Institute Stockholm Sweden