Adolescent sexuality is a relevant public health issue, as it affects risk to contract HIV and other sexually transmitted infections. The assessment of prevalence of sexual intercourse among adolescents may guide policies and programmes aimed at reducing the transmission of sexually transmitted infections among this age group. Using data from the Thailand Global School-Based Student Health Survey (GSHS) 2008, we assessed the prevalence of sexual intercourse in the last 12 months and its associated factors among adolescents (N = 2758). Overall the prevalence of sexual intercourse in the past 12 months was 11.0% (14.6% males and 7.6% females). Variables positively associated with the outcome in multivariable analysis were male gender (OR = 1.66; 95% CI 1.14-242), older age, ≥15 years (OR = 2.60, 1.80-3.74), current alcohol use (OR = 2.22, 1.46-3.36), psychosocial distress (OR = 2.11, 1.44-3.09) and among females current smoking (OR = 5.47, 1.62-18.48), lifetime drug use (AOR = 4.35, 1.04-18.3) and lack of parental or guardian bonding (AOR = 0.51, 0.27-0.97). Efforts to control unhealthy lifestyles (substance use) and psychosocial distress may impact on adolescents' sexual activity.
Keywords: Adolescent sexuality; HIV and AIDS; Thailand; protective factors; sexual intercourse; substance use.