1 Statens Serum Institut, Department of Epidemiology Research, DK-2300 Copenhagen S, Denmark and Center for Sexology Research, Department of Clinical Medicine, Aalborg University, DK-9000 Aalborg, Denmark Statens Serum Institut, Department of Epidemiology Research, DK-2300 Copenhagen S, Denmark and Center for Sexology Research, Department of Clinical Medicine, Aalborg University, DK-9000 Aalborg, Denmark MFR@ssi.dk.
2 Statens Serum Institut, Department of Epidemiology Research, DK-2300 Copenhagen S, Denmark and Center for Sexology Research, Department of Clinical Medicine, Aalborg University, DK-9000 Aalborg, Denmark.