This article is number 16 in a series of 21 articles on tools for evidence-informed health policymaking. Decisions about health programmes and policies cannot be made based on evidence alone. Judgements are always required, including judgements about whether the anticipated benefits outweigh the downsides, how important the impacts are, the resources that are required to implement the policy or programme, and the extent to which the policy or programme is a priority in relationship to other ways in which those resources might be used.