Behavioural and developmental factors mean that adolescents who initiate sexual intercourse early may be at an increased risk of adverse sexual health outcomes at the time of first sex and later in life. In an Irish context, there is insufficient knowledge about the specific correlates of early sexual initiation. This research explores relationships between contextual socio-demographic, health and lifestyle factors and the timing of first sexual intercourse among 15⁻17-year-olds in Ireland. Multiple regression analysis was carried out in conjunction with Multiple Imputation using data collected through the 2014 Health Behaviour in School-Aged Children Ireland study on a sample of 879 sexually active adolescents.

The socio-demographic and lifestyle factors measured were a stronger predictor of age of sexual initiation among girls than boys. Risk behaviour initiation was significantly related to age of sexual initiation for adolescents, while alcohol use/drunkenness and unhealthy food consumption was significant among girls only. Family support and number of male friends were significant predictors for boys only. The study highlights the need for holistic approaches to sexual health promotion and provides a foundation for the development of alternative strategies and policies aimed at reducing negative health, well-being, educational and economic outcomes.

Discussion: The study found that initiation of risk behaviours such as smoking, alcohol use, drunkenness or cannabis at younger ages was predictive of early sexual initiation among girls and boys. Sexual risk behaviours and smoking, alcohol and substance use have consistently been linked in the literature and are often considered to occur in clusters thus the finding that initiation of these behaviours may be related in an Irish context is no surprise..........