Why do we care about evidence synthesis? An introduction to the special issue on systematic reviews

Systematic reviews are currently in high demand in international development. At least 100 new reviews are ongoing or already completed on a range of topics across the board in international development, many of which were commissioned by policy-making agencies. These new reviews need to be based on answerable questions, using methods of analysis and reporting which are appropriate for social and economic development programmes and relevant to users. This introductory paper lays out why we believe systematic reviews should be an important component of evidence-informed development policy and practice. It concludes by introducing the papers collected in this issue, which aim to demonstrate how reviews can be made to live up to the promises generated around them.