1. Department of Biostatistics Institute of Basic Medical Sciences; University of Oslo; Oslo Norway
2. Department of Etiological Research; Cancer Registry of Norway; Oslo Norway
3. Department of Medical Epidemiology and Biostatistics; Karolinska Institutet; Stockholm Sweden
4. Health Economics and Drugs Unit Norwegian Knowledge Centre for the Health Services; Oslo Norway
5. Department of Community Medicine; University of Tromsø; Tromsø Norway
6. Department of Epidemiology; Harvard School of Public Health; Boston MA
7. Department of Genetic Epidemiology; Folkhälsan Research Center; Helsinki Finland