ABSTRACT
PURPOSE: To evaluate the efficacy of an abstinence-centered sex education program in adolescent pregnancy prevention, the TeenSTAR Program was applied in a high school in Santiago, Chile. METHODS: A total of 1259 girls from a Santiago high school were divided into three cohorts depending on the year they started high school: the 1996 cohort of 425 students, which received no intervention; the 1997 cohort, in which 210 students received an intervention and 213 (control group) did not; and the 1998 cohort, in which 328 students received an intervention and 83 (control group) did not. Students were randomly assigned to control and intervention groups in these cohorts, before starting with the program. We conducted a prospective, randomized study using the application of the TeenSTAR sex education program during the first year of high school to the intervention groups in the 1997 and 1998 cohorts. All cohorts were followed up for 4 years; pregnancy rates were recorded and subsequently contrasted in the intervention and control groups. Pregnancy rates were measured and Risk Ratio with 95% confidence interval were calculated for intervention and control groups in each cohort. RESULTS: Pregnancy rates for the intervention and control groups in the 1997 cohort were 3.3% and 18.9%, respectively (RR: 0.176, CI: 0.076-0.408). Pregnancy rates for the intervention and control groups in the 1998 cohort were 4.4% and 22.6%, respectively (RR 0.195, CI: 0.099-0.384). CONCLUSIONS: The abstinence-centered TeenSTAR sex education intervention was effective in the prevention of unintended adolescent pregnancy.