Limited effectiveness of HIV prevention for young people in sub-Saharan Africa: studying the role of intervention and evaluation.

On average, 2,500 young people (15-24 years) get -infected with HIV every day; 80% of which live in sub-Saharan Africa. Since no cure or vaccine is available, reducing sexual risk behaviour in this group is crucial in tackling the epidemic. The general objective of this doctoral study was to improve the effectiveness of HIV prevention interventions for young people in sub-Saharan Africa. First, we assessed the overall effectiveness of such interventions (systematic literature review, meta-analysis). Secondly, we evaluated a school-based peer-led HIV prevention interventions in Rwanda (longitudinal, non-randomized controlled trial), to get insight into how interventions are developed, implemented and evaluated. While the first two objectives demonstrated limited effectiveness, the third objective aimed to identify reasons for this limited effectiveness: a) baseline characteristics of -respondents that predict participation were identified (using data from objective 2); b) we studied determinants of young people's sexual behavior using a qualitative 'mailbox study' that assessed the spontaneous thoughts of Rwandan adolescents on sexuality; c) we assessed the role of one specific structural factor: -education (literature review and analysis of existing datasets); d) we assessed the theoretical underpinnings of existing HIV prevention interventions for young people in sub-Saharan Africa (literature review). Based on these studies, we discuss two main reasons for the observed limited effectiveness: factors associated with the intervention (strong focus on cognitions and moral, and implementation issues), and with evaluation (design, power, indicators). Recommendations for improving interventions, evaluations and for further research are provided.