It should be noted that several limitations in the study design may have contributed to the lack of intervention findings. This study examined the timing of onset of problem behaviors and risky sex outcomes through age 17. In addition, the assessment of risky sexual activity was somewhat limited in the Fast Track data through age 17, as youth were not asked to report on multiple partners or other aspects of sexual activity until age 18. Preliminary analyses of follow-up data collected during early adulthood suggest that intervention effects may emerge in some areas of risky sexual activity associated with HIV/AIDS, including multiple partners and condom use. If so, such findings would be consistent with other patterns observed in the Fast Track data in which intervention effects that were evident in elementary school diminished during the middle school years (CPPRG 2010a) but re-emerged in later high school and early adulthood (CPPRG 2010b; 2012). In addition, extended analyses that move beyond these “intent to treat” outcome analyses may be useful, in terms of identifying subgroups for whom the Fast Track prevention program was more effective, and thereby generating ideas for strengthening future prevention program designs that could be tested in future trials.
