The results support the major hypothesis motivating the study: effects on mediators of behavior change that were introduced during the media intervention were sustained to the follow-up assessments at least 18 months after the intervention ended. Thus, the study shows that mass media influence delivered over an extended period, when adolescents were beginning to learn patterns of behavior associated with sex, persisted after the media program ended. Media exposure was able to produce differences in respondent levels of the thematic mediators although the media effect was the strongest for the Selection and Pleasure mediators. All three mediators were (negatively) associated with intention, although Selection and the Negotiation performed the best. The intention/behavior correlation (the C parameter) was always significant even when the temporal lag was as much as 18 months (i.e., between intention measured at 18 months and behavior measured at 36 months, the average number of days between the end of the media campaign and the 36 month assessment was 306 days).
The Selection mediator performed well at all stages of the meditational process. This result is consistent with past research using survey, experimental, and qualitative research 30–32
that demonstrates that adolescents (and adults) use informal rules (e.g., “heuristics”) in an attempt to choose safe sex partners. The media intervention emphasized that one cannot tell how many partners someone has had in the past and therefore that one should always use a condom when having sex. Young people (as well as adults) are particularly susceptible to discontinuing condom use after initiating sex with a new partner for as short a period as a few weeks 33, 34
. Nevertheless, even if such partnerships are monogamous, they will not protect one from transmission of STIs if a partner was infected by a previous partner. Project iMPPACS is the first example to our knowledge of a media intervention that attempted to change this problematic practice.
Media effects on the Pleasure mediator were apparent in five of six data periods, but Pleasure had the weakest association with condom use intention. Nonetheless, the Pleasure mediator was an important target in the media intervention because young people often believe that condoms will interfere with sexual enjoyment. Although it was not strongly associated with intention to use condoms apart from the other mediators, the Pleasure mediator may have played a role in supporting the other belief changes that were encouraged by the media program. Youth could be more motivated to use condoms if they are not under the impression that condoms are used by people who don’t care about their negative effects. Indeed, the media program emphasized that condoms actually enhance pleasure because they reduce worry about contracting a STI.
The Negotiation mediator showed the fewest treatment effects but was consistently associated with condom use intention. This mediator is particularly important in the context of a media intervention because it involved expectations about how sexual partners would respond to a request to use a condom. Youth in the media cities could more confidently expect their potential partners to respond favorably to such requests because everyone in the city was likely to have been exposed to the media program. This process of normative change may explain why the Negotiation mediator took some time to show effects of the media program. Youth could more confidently believe that their peers and partners would respond favorably to condom-use requests as the media program continued. They may have been less sure of this possibility in the early stages of the media program.
We restricted the present study to vaginal sex because we did not have a measure of intention for anal or oral sex. Hence, we cannot say that the intervention had long-term effects for those engaging in these forms of sex. Finally, our results are based on self-reports of sexual behavior. However, we used ACASI for all our assessments, and this was likely to decrease reporting bias 35
. Hence, the results are likely to accurately reflect the rates of unprotected sex occurring in this population.
Media Interventions for Adolescents
The findings from project iMPPACS strongly support the use of media interventions directed to adolescents as a way to produce long-lasting effects on sexual risk behavior. The media program not only increased condom use among the highest risk youth within the first 8 months of its introduction 12
but it also reduced the trajectory of unsafe sex among the broader youth audience as the program continued15
. Finally, it maintained the effects of an STI screening intervention carried out face-to-face in the community 14
. Thus, mass media provide an effective way to enhance the durability of interventions carried out on the ground while they independently change sexual norms and behaviors among youth on their own.