1. Section of Biostatistics; University of Copenhagen; Øster Farimagsgade 5, POB 2099 Copenhagen K DK-1014 Denmark
2. Unit of Statistics, Bioinformatics and Registry; Danish Cancer Society Research Center; Strandboulevarden 49 Copenhagen Ø DK-2100 Denmark
3. Department of Epidemiology and Biostatistics; University of California; 550 16th Street, 2nd floor San Francisco CA 94158 U.S.A.
4. Unit of Virus, Lifestyle and Genes; Danish Cancer Society Research Center; Strandboulevarden 49 Copenhagen Ø DK-2100 Denmark
5. Department of Gynecology, Rigshospitalet; University of Copenhagen; Blegdamsvej 9 Copenhagen Ø DK-2100 Denmark