The purpose of Cochrane reviews is to facilitate healthcare decision-making by patients and the general public, clinicians, administrators, and policy makers. A clear statement of findings, a considered discussion and a clear presentation of the authors’ conclusions are important parts of the review. In particular, the following issues can help people make better informed decisions and increase the usability of Cochrane reviews.
Information on all important outcomes, including adverse outcomes.
The quality of the evidence for each of these outcomes, as it applies to specific populations, and specific interventions.
Clarification of the manner in which particular values and preferences may bear on the balance of benefits, harms, burden and costs of the intervention.
A ‘Summary of findings’ table, described in Chapter 11 (Section 11.5), provides key pieces of information in a quick and accessible format. Review authors are encouraged to include such tables in Cochrane reviews, and to ensure that there is sufficient description of the studies and meta-analyses to support their contents. The Discussion section of the text should provide complementary considerations. Authors should use five subheadings to ensure they cover suitable material in the Discussion section and that they place the review in an appropriate context. These are ‘Summary of main results (benefits and harms)’; ‘Overall completeness and applicability of evidence’; ‘Quality of the evidence’; ‘Potential biases in the review process’; and ‘Agreements and disagreements with other studies or reviews’. Authors’ conclusions are divided into ‘Implications for practice’ and ‘Implications for research’.
Because Cochrane reviews have an international audience, the discussion and authors’ conclusions should, so far as possible, assume a broad international perspective and provide guidance for how the results could be applied in different settings, rather than being restricted to specific national or local circumstances. Cultural differences and economic differences may both play an important role in determining the best course of action. Furthermore, individuals within societies have widely varying values and preferences regarding health states, and use of societal resources to achieve particular health states. Even in the face of the same values and preferences, people may interpret the same research evidence differently. For all these reasons, different people will often make different decisions based on the same evidence.
Thus, the purpose of the review should be to present information and aid interpretation rather than to offer recommendations. The discussion and conclusions should help people understand the implications of the evidence in relation to practical decisions and apply the results to their specific situation. Authors should avoid specific recommendations that depend on assumptions about available resources and values. Authors can, however, aid decision-making by laying out different scenarios that describe certain value structures.
In this chapter we address first one of the key aspects of interpreting findings that is also fundamental in completing a ‘Summary of findings’ table: the quality of evidence related to each of the outcomes. We then provide a more detailed consideration of issues around applicability and around interpretation of numerical results, and provide suggestions for presenting authors’ conclusions.