Evidence Synthesis and Systematic Reviews

Evidence syntheses are any sort of project designed to systematically collect evidence on a topic and present it in a clear and reproducible way. The methodology is specifically designed to reduce bias and to be reproducible. As with a scientific experiment, if someone else follows the procedure they should get the same or very similar results: the literature collected is the data, the search and analysis are the methods, and the discussion and conclusion should follow obviously from those results.

The reduction of bias is very important in the framework of evidence synthesis. If you are basing a practice or policy decision on evidence, you want as much relevant evidence as possible, not just the evidence that agrees with your assumptions, or that was done by the people you already know about.

The choice of search terms, search sources, and selection decisions is crucial to doing an unbiased review. Even the choice of search terms can skew results: "Several critics also noted that in reviewing the scientific literature, the authors deliberately sought out papers on insect declines, quite possibly overlooking research showing stable or increasing populations." (One of those critiques:  https://doi-org.scsu.idm.oclc.org/10.1111/gcb.14608)

Yes, they are, but not just a healthcare thing anymore.

Evidence syntheses, by various names, can be used in any field where practice or policy decisions are made based on research evidence.

• Clinical care and practice
• Education
• Management
• Genetics
• Psychology
• Social work
• Nutrition
• Exercise
• Criminal justice
• Environmental conservation
• Sustainable development
• Citation/publication analysis
• Public policy on any topic
• ...to name just a few.

And a structured, systematized collection of research is valuable in any field of research.