Improving the Quality and Utility of Evidence Synthesis
Systematic reviews and evidence synthesis can be a valuable resource to underpin the development of evidence-informed policy and practice by providing readily prepared syntheses of quality-appraised evidence. Despite the strong research and policy commitments to the notion of ‘evidence-based policy’ for public health in the UK and internationally, there is often substantial mismatch between public health policies and the available evidence. A key reason for this mismatch is that while decision-makers highlight the potential utility of systematic reviews, in reality there are a number of issues which threaten the utility of systematic reviews.
Systematic reviews addressing public health questions which are prioritised by policymakers are often complex and methodologically challenging. This has implications for the resources and skills required to produce a synthesis which is reliable, and ultimately may threaten the utility of the final review product. Regardless of how rigorous and comprehensive a review is, syntheses that are not timely may no longer be relevant once completed. The nature of available evidence may also present challenges to the rigour and readability of complex reviews. Statistical synthesis is often not appropriate, the resulting narrative syntheses are often lengthy, and the link between the findings of the evidence synthesis and the review conclusions can be opaque.
We focus on ways to improve the reliability and utility of systematic reviews addressing public health policy relevant questions, as well as conducting new substantive reviews to inform decision-making. The workstream includes work to improve the transparency of non-statistical methods of synthesis, interpretation of complex reviews, assessing risk of bias in non-randomised studies, in addition to a range of systematic reviews. Although much of the core methodological work uses public health examples, this work has wider relevance application to complex reviews in other topics.