Sexual intercourse, age of initiation and contraception among adolescents in Ireland: findings from the Health Behaviour in School-aged Children (HBSC) Ireland study

BACKGROUND: The need to tackle sexual health problems and promote positive sexual health has been acknowledged in Irish health policy. Young people’s sexual behaviour however remains under-researched with limited national data available. METHODS: This study presents the first nationally representative and internationally comparable data on young people’s sexual health behaviours in Ireland. Self-complete questionnaire data were collected from 4494 schoolchildren aged 15–18 years as part of a broader examination of health behaviour and their context. The prevalence of sexual initiation, very early sexual initiation (< 14 years) and non-condom use at last intercourse are reported and used as outcomes in separate multilevel logistic regression models examining associations between sociodemographic characteristics, lifestyle characteristics and young people’s sexual behaviours. RESULTS: Overall, 25.7% of boys and 21.2% of girls were sexually initiated. Older age was consistently predictive of initiation for both boys and girls, as were alcohol, tobacco and cannabis involvement, living in poorer neighbourhoods and having good communication with friends. Involvement in music and drama was protective. Very early sexual initiation (< 14 years) was reported by 22.8% of sexually initiated boys and 13.4% of sexually initiated girls, and was consistently associated with rural living, cannabis involvement and bullying others for both. Boys’ very early initiation was predicted by alcohol involvement, receiving unhealthy food from parents and taking medication for psychological symptoms, whereas better communication with friends and more experience of negative health symptoms were protective. Girls’ very early initiation was predicted by being bullied and belonging to a non-Traveller community, whereas taking medication for physical symptoms and attending regular health checks was protective. Condom use was reported by 80% of sexually initiated students at last intercourse. Boys’ condom use was associated with older age, higher family affluence, bullying others, more frequent physical activity and health protective behaviours. For girls, condom use was predicted by belonging to a non-Traveller community, healthy food consumption, higher quality of life and being bullied, whereas taking medication for physical and psychological symptoms was associated with non-condom use. CONCLUSIONS: These nationally representative research findings highlight the importance of focusing on young people as a distinct population subgroup with unique influences on their sexual health requiring targeted interventions and policy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-018-5217-z) contains supplementary material, which is available to authorized users.