What is evidence synthesis?
Evidence synthesis (sometimes called knowledge synthesis) is the process of gathering all relevant information on a given topic. We generally do this by searching the academic and non-academic literature to learn what is known and unknown. We use evidence synthesis to identify gaps in our body of knowledge, answer research questions, and inform decision-making using the best possible information.
What can evidence synthesis look like?
All high-quality research projects should have some element of evidence synthesis. In many cases, researchers will use literature searching to provide background and justification for a project. In traditional research papers, this process is referred to as a literature review, and is usually featured at the beginning of a manuscript to provide context for what is to follow. Literature reviews are a good first step when considering whether or not to pursue a research question.
In other cases, evidence syntheses stand as a type of research project on their own. Systematic reviews and meta-analyses are two of the most common types of evidence syntheses. Other examples include scoping reviews, rapid reviews, and realist reviews. These review types all use systematic methods to gather everything that is known about a topic, and follow a common six-step process:
- Formulate a research question
- Establish clear criteria on which literature should be included and excluded
- Identify all potentially relevant studies
- Apply the inclusion/exclusion criteria
- Extract data (and, often, critically appraise studies)
- Summarize and analyse the evidence
Systematic reviews are considered to be the highest level evidence available because they are not selective; their purpose is to synthesize everything that has ever been reported about a topic, drawing from the knowledge of the world's researchers.
Why is evidence synthesis important?
In today's digital era, it can seem as if we are confronted with an endless sea of information. It is impossible for any one person to process it all. Evidence synthesis allows us to see the "big picture" and be confident that we are making good decisions. It also helps reduce research waste by taking stock of what has already been done.
The MSSU can help you navigate the sea of information.
Our Evidence Synthesis Coordinator can work with you to define your research question, locate background literature, develop systematic review searches, offer training in evidence synthesis methods and topics, and more. To request our services, please fill out our support request form here.