Age at first experience of intercourse among Norwegian adolescents: a lifestyle perspective.

Age at first intercourse among Norwegian adolescents was studied by means of survival analysis. The data stemmed from a nation-wide survey of 3000 Norwegian adolescents aged 17-19, yielding a response rate of 61.8%. Median age at first intercourse was 17.3 years among girls and 18.0 years among boys. By means of Cox regression analysis associations between age at onset of intercourse and some correlates were estimated. Age at first intercourse was significantly associated with educational aspirations, smoking behaviour, alcohol consumption, peer affiliation, and frequency of visiting a discotheque. These inter-relationships confirm that age at onset of intercourse comprise an important indicator of the lifestyle of an individual. In order to influence sexual behaviour of adolescents it may thus be appropriate to employ health promotion activities focusing upon environmental and structural factors, as a supplement to traditional methods of sex education.