Study Details

A subsequent study by a separate group of researchers evaluated the program when implemented on a broader scale and with a more broadly-defined target population. The study used a randomized controlled trial involving adolescents recruited from schools and community-based organizations across three states (Arizona, California, and Massachusetts). Study participants were randomly assigned to either a treatment group that was offered the program during school or as part of an afterschool program, or to a control group that received their regular school curriculum and (in some sites) a healthy lifestyle curriculum or other after-school activities. Surveys were administered before random assignment (baseline), and six and 18 months after study enrollment.

For the full study sample, six months after study enrollment, the study found no statistically significant program impacts on the likelihood of respondents reporting ever being sexually active, being sexually active in the last 90 days, or having sex without a condom or other form of birth control in the last 90 days. Among the subgroup of study participants who were sexually experienced at baseline, the study found evidence of an adverse effect six months after study enrollment: adolescents in the intervention group were significantly more likely to report having had sexual intercourse in the previous 90 days. This difference was not observed in the subgroup of study participants who had never been sexually active at baseline.

For the follow-up that occurred 18 months after study enrollment, the study found no evidence of statistically significant programs impacts on the likelihood of being sexually active in the last 90 days or having sex without a condom or other form of birth control in the last 90 days, for the full sample. Among the subgroup of adolescents who were not sexually experienced at baseline, the study found no evidence of statistically significant program impacts on sexual initiation. At the 18-month follow-up, the study also found no evidence of statistically significant program impacts on the likelihood of becoming pregnant or getting someone pregnant since baseline, or being diagnosed with a STI in the last 12 months.

The study findings are not directly comparable with those reported in the initial study of the program (Villaruel et al. 2006) because they estimate program impacts at a single time point, whereas the initial study reported impacts averaged across multiple follow-up periods.

The study also examined program impacts on attitudes, motivation, skills, and intentions related to sexual activity, as well as subgroup impacts by race. Findings for these outcomes and subgroups were not considered for the review because they fell outside the scope of the review.