Women's sexual behavior. Population-based study among 65 000 women from four Nordic countries before introduction of human papillomavirus vaccination.

Objective. Sexual behavior is of public health interest because of the association with reproductive health and sexually transmitted infections such as human papillomavirus, which is the causal factor of cervical cancer. The aim of the study was to describe patterns in women's sexual behavior in four Nordic countries. Design. Population-based cross-sectional study. Setting. Denmark, Iceland, Norway, and Sweden (November 2004-June 2005). Population. A random sample of 18-45-year-old women from the female population in the four participating Nordic countries. The participation rate ranged from 81.3% in Denmark to 54.5% in Iceland. In total, 65 623 women were included. Methods. Each participant completed a structured questionnaire containing questions about sociodemographic factors, lifestyle factors and sexual behavior. Main outcome measures. Age-specific and country-specific descriptive measures of sexual behavior, notably age at first intercourse and lifetime number of partners. In addition, risk factors for having had multiple (>10) sexual partners were examined. Results. Overall, median age at first intercourse was 16, and 30.2% (95% CI: 29.9-30.6) of the participating women reported having had ≥10 partners. There was great variation with birth cohort but limited variation between countries. The main correlates of multiple sexual partners were increasing age at enrollment, a higher alcohol intake and young age at first intercourse. Conclusions. These measurements of sexual behavior before the introduction of national human papillomavirus vaccination programs will form the basis for a comparison with a similar survey performed after vaccination has been introduced. [ABSTRACT FROM AUTHOR]