This study aimed to identify the determinants of preventive intention on sexual behaviours using the theory of planned behaviour among the junior high school students in lower northern region of Thailand. Acrosssectional study with self-administered questionnaire was employed to collect survey data. Amultistage sampling technique was used to select informants. The strongest positive association with preventive intention on sexual behaviours was found for perceived self-efficacy towards preventing sexual intention. Perceived self-efficacy, perceived social belief, and perceived peer pressure/social influence had positive and significant (P< 0.001) effect on preventive intention on sexual behaviours, while perceived attitude had negative and significant (P< 0.001) effect on preventive intention on sexual behaviours. Students' behavioural intention significantly predicted preventive intention on sexual behaviours among the junior high school students in lower northern region of Thailand. The school administrators could use the theory of planned behaviour to promote sexual education programme for junior high school students. Theory of planned behaviour; preventive intention; sexual behaviours; junior high school students

This study investigated factors affecting the preventive intention on premarital sexual behaviours among junior high school students in lowernorthern region of Thailand. A cross-sessional study was conducted. Stepwise regression model was used to run multiple linear regression. Self-awareness was the best predictor of the preventive intention on premarital sexual behaviours for having the biggest coefficient (Beta coefficient equal to 0.696, t = 19.183, P = 0.001). Self-awareness had positive and significant effect on preventive intention on premarital sexual behaviour. High education levels of parents had more positive and significant effects on the preventive intention on premarital sexual behaviour compared to low levels of education. Consulting parents had more positive and significant effect on premarital sexual behaviours compared to not consulting any person. Thai sexual education needs to be extended to parents of students to induce the preventive intention on premarital sexual behaviours among junior high school students.

This study aimed to explore factors perceived to affect the intention of premarital sexual behaviours among junior high school students in Muang District, Thailand. A stratified random sampling technique was employed to select three schools out of ten public junior high schools. A situation analysis was conducted following a focus group discussion and in-depth interview. The informants included six junior high school students, five parents, three teachers, two health professionals and two school administrators. A thematic analysis was employed for the data analysis. Results illustrated negative attitude, social media, the internet use, socio-environmental space, peer pressure, social belief, low self-efficacy, generation gap and sexual education were the factors perceived to affect the intention of sexual behaviours. An integrated implementation of a comprehensive sexual education was the way forward to increasing self-efficacy.