Abstract
Comprehensive sexuality education (CSE) prepares young people to make informed decisions about their sexuality. A review by the Institute of Research and Evaluation that analysed 43 CSE studies in non-US settings found the majority to be ineffective and concluded that there was little evidence of the effectiveness of CSE. We reanalysed the review to investigate its validity. We found several weaknesses with the review's methodology and analysis: (1) there was an absence of a clearly articulated search strategy and specific eligibility criteria; (2) the authors put forth criteria for programme effectiveness but included studies that did not collect the data needed to show programme effectiveness and thus several studies were determined to be ineffective by default; (3) the analytical framework minimised positive intervention effects and privileged negative intervention effects; and (4) there were errors in the data extracted, with 74% of studies containing one or more discrepancies. Overall, our reanalysis reveals that the IRE review suffers from significant methodological flaws and contains many errors which compromise its conclusions about CSE. Our reanalysis is a tool for the international community to refute CSE opposition campaigns based on poor science.