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Evidence Synthesis & Systematic Review Research

This guide provides an introduction to evidence synthesis research methods.

Questions to answer before you begin

Evidence synthesis projects require a significant time commitment, especially if you are undertaking something that is not considered one of the traditional review types. Before you commit this time, please review the questions below and develop solid answers so that you are not surprised along the way. Doing this pre-work can increase your chances of successfully taking your project to completion.

Is your project unique?

Given the amount of time and effort these projects take, be sure to do exploratory searches to identify if your project is unique. Do not skip this step!

If similar questions have been studied or are in progress, you may find it challenging to get your project published. Think about different aspects of the topic or question that your project might be able to tackle, instead.

 

Do you have the team and expertise to conduct the project?

In contrast to a traditional narrative literature review (usually done by an individual researcher), many other evidence synthesis projects (e.g. systematic reviews, scoping reviews, rapid reviews, etc.) require a team.

 

Core Team

A minimum of three (3) individual members is recommended to fill the following roles:

  • 2 Reviewers | There must be at least two (2) individuals who will each review every reference for every level of review
  • 1 Tie-Breaker | There must be one (1) individual who rounds out the consensus process or acts as a tie-breaker when resolving disagreements between the two reviewers

 

Consider Other Possible Team Roles

There are several other team roles and responsibilities that should be considered, including those that follow. Note that several roles/responsibilities may be filled by a single individual with corresponding skills.

  • Subject Expert | Strong familiarity and comfort with the field(s) related to your research question(s); not all team members need to be an expert in the subject matter
  • Methodological Expert | Strong familiarity and comfort with the systematic review methodology; ideally having past experience on a different systematic review team
  • Information Retrieval Expert | Skilled at designing, troubleshooting, executing, and documenting a comprehensive search strategy; familiarity and comfort with relevant databases; often has a background in library and information sciences
  • Project Manager | Ensures the project stays on track in terms of timeline, budget, and meeting methodological expectations; ideally having experience with systematic review management in particular including methodological requirements as well as software and tools
  • Statistician | Familiarity with statistical synthesis methods including meta-analyses; ideally having experience running meta-analyses and/or as a member of a different systematic review team

 

Consider Stakeholder and Community Engagement

Systematic reviews are designed to provide the "evidence-base" in "evidence-based" decision making, policy, practice guidelines, etc. Therefore, you should consider the communities and stakeholders that might be interested in the outcomes of your review, and engage with them throughout the review, especially during the planning phases.

Check out the Cochrane Collaboration's Involving People resource, Dr. Neal Haddaway's Stakeholder and Synthesis repositoryand the EPPI Centre's Engaging Stakeholders Evidence and Uncertainty.

 

Credit: "Team" (Virginia Tech University Libraries) adapted by OSU Libraries & Press under CC BY-NC-SA 4.0.

How much time do you have to complete an evidence synthesis project?

While there is no definitive answer to how long these projects take, rough estimates range from 6-12+ months.

The PredicTER tool can be used to generate some estimates for systematic review and systematic mapping projects, specifically. The tool will give time estimates for various phases in the projects.