Evidence Synthesis

Evidence Synthesis

What is evidence synthesis?

Evidence synthesis is the bringing together and interpretation of knowledge on a specific topic. Evidence synthesis methods allow individual studies to be considered in the context of the wider evidence base. Sometimes individual studies can provide conflicting results and different experts can have different opinions on a topic. Synthesising all available evidence on a topic using transparent methods enables the strength of the evidence base to be assessed and gaps to be identified.

Why you may want to include evidence synthesis support

  • to ensure explicit methods are used to limit inclusion bias – extensive searching limits publication bias and results in more trustworthy conclusions;
  • to succinctly summarise large amounts of information for audiences such as clinicians or policy makers, which may reduce time to implementation;
  • to highlight research gaps – identify what is known and what is unknown;
  • to make formal comparisons of studies.

What expertise can an evidence synthesis advisor offer?

  • refine your research question;
  • advice on the appropriate analysis method to answer your question;
  • advice on approaches to searching for information on your topic;
  • advice on managing and reporting the process of systematic reviewing.

What to think about before a meeting with an evidence synthesis advisor

  • define your review question very clearly;
  • think about what type of review/output will answer the question.

Useful Resources

Bragge P, Clavisi O, Turner T, et al. The Global Evidence Mapping Initiative: Scoping research in broad topic areas. BMC Medical Research Methodology 2011;11:92.

Dixon-Woods M, D Cavers, S Agarwal et al.  Conducting a critical interpretive synthesis of the literature on access to healthcare by vulnerable groups.  BMC Med Res Methodol.  2006; 6:35-

Dixon-Woods M, S Agarwal, D Jones et al.  Synthesising qualitative and quantitative evidence: a review of possible methods.  J Health Serv Res Policy.  2005; 10:1:45-53

Greenhalgh T.  How to read a paper: papers that summarise other papers (systematic reviews and meta-analyses). BMJ. 1997; 315: 672-