Improving the usefulness and practice of evidence synthesis: views and experiences of public health decision makers and review authors in the UK

Background: The preparation of rigorous systematic reviews to address public health policy questions presents various methodological challenges. The Cochrane Public Health Group conducted a consultation that aimed to explore the usefulness of public health systematic reviews, and key issues hindering timely production of useful, policy relevant reviews.<p></p> Methods: We purposively sampled users of reviews, commissioners, and authors with diverse experience of using and conducting reviews in the UK. Interview data were coded using framework analysis, and the range and consistency of responses were explored in the analysis. We obtained ethics approval from the University of Cardiff.<p></p> Findings: Telephone interviews were conducted with 14 policy makers and 13 systematic review authors. Systematic reviews were valued by decision makers. Useful reviews needed to be timely and clearly communicated, to ask relevant questions, and be actionable and applicable to specific contexts. There were concerns that extremely rigorous reviews were less useful, for example by excluding evidence from non-randomised studies. There was frustration with reviews that had a narrow scope and did not report on emerging mechanisms for health effects. Authors described the challenges of completing large, complex reviews, highlighting resource constraints and reviewer capacity as important issues. Lack of methodological expertise was reported as a major barrier to producing useful reviews. Involvement of policy makers in the review process was viewed as important for improving communication and relevance of reviews.<p></p> Interpretation: The findings support the assertion that systematic reviews have a crucial role in knowledge exchange, and the data reiterate recommendations for clear communication of useful, timely evidence for evidence users. Issues specific to systematic reviews point to substantial challenges in the production of useful systematic reviews. The consultation was small, limiting the generalisability of the findings. Nevertheless, the apparent tension between producing timely, actionable findings for decision makers and the resource implications in producing complex reviews that include diverse sources of evidence presents a serious threat to the usefulness of reviews. Greater engagement with review users throughout the review process to define review scope, and interpretation of findings could improve the usefulness of reviews. In addition, further support to increase methodological capacity for broad public health reviews is required