Introduction: Policy makers are key potential clients of evidence on effectiveness in health care interventions. They have needs and perspectives which should be understood by those seek to provide such evidence. The experience of the National Advisory Committee on Health and Disability (National Health Committee) is described with respect to its programme to promote the use of evidence based guidelines as a major part of the language and culture in the health sector. In particular, the experience in developing and implementing tools for assessing clinical priority have shown major gaps in evidence of effectiveness. Nevertheless, for coherent pragmatic policy to be developed, the gaps must be filled with lower levels of evidence and different types than customarily summarised in Cochrane Collaboration systematic reviews.

Discussion: Implications as to how Cochrane Collaboration work might become more immediately useful and relevant to policy makers are discussed.