RESUMEN
The African Youth Alliance (AYA) was a partnership to improve adolescent sexual and reproductive health, and prevent HIV/AIDS in Botswana, Ghana, Tanzania and Uganda. The AYA model was a comprehensive range of integrated interventions, implemented concurrently and at scale using a multi-sectoral approach. AYA was funded for five years (2000-2005) with $56.7 million from the Bill and Melinda Gates Foundation. Over 35,000,000 stakeholders were reached through media campaigns, almost 400,000 young people received Life Planning Skills training, and over 2,500,000 visits were made by young people to static clinics and outreach services. A post-test evaluation was conducted by John Snow Inc. (JSI) in 2006 and combined case-control and self-reported exposure design. Case-control design data were analyzed using Propensity Score Matching (PSM), and the Self-Reported Exposure design data were analyzed using PSM and Instrumental Variable (two-stage regression) (IV). The results show AYA's significant and positive treatment effects on sexual knowledge, attitudes, and behaviours. The research suggests a comprehensive, multi-component approach such as AYA's can be effective in improving some key ASRH variables.