Abstract
Objective. To examine incidence and risk factors of partner change among Norwegian teenage girls attending youth health clinics. Design. Prospective cohort study. Setting. Study subjects were 691 girls, aged 16 to 19 years, who participated in a study on prescription of oral contraceptives at three youth health clinics in the city of Trondheim, Norway. Methods. Eligible for analysis were participants who were sexually active, and who returned for at least one follow-up visit more than 120 days after study start. All demographic and behavior data were collected through interview by public health nurses. All analyses were performed with SPSS for Windows (version 15.0) using chi-square test, survival analyses and logistic regression. Main outcome measure. New sexual male partners. Results. Four out of five girls (80%) did not have any new partner during the study period of 12 months. From survival analyses the 12-month incidence rate were 29.8 (95% CI: 25.3–34.1) and 10.6 per 100-women months (95% CI: 7.3–13.9) for one or two or more partners, respectively. Predictors of partner change were partner change during the last six month prior study start, being single and sexual debut within three years after menarche. Conclusion. Being in a regular relationship with a boyfriend reduce considerably the risk of having a new sexual partner. Recent history of partner change is the strongest predictor of future partner change.