"A systematic review (SR) attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made.
Key characteristics of a systematic review are:
Higgins, Julian. Cochrane Handbook for Systematic Reviews of Interventions. Hoboken, NJ, USA: John Wiley & Sons, 2009. https://training.cochrane.org/handbook/archive/v5.0.2/.
Define the question
Check for recent systematic reviews and protocols
Create a review protocol, and register it if appropriate
Design and conduct reproducible, comprehensive searches
Organize and screen search results
Appraise the quality of the studies
Analyze / synthesize data
Write the review
Multiple guidelines and standards exist to aid researchers in the creation of high quality systematic reviews and other evidence syntheses.
Reviews may be conducted in accordance to specific internationally-established guidelines, such as Cochrane, the Joanna Briggs Institute, the Campbell Collaboration, and the Collaboration for Environmental Evidence. These follow the most rigorous standards for planning, executing and reporting this type of research. Even if you are not conducting a review for one of these organizations, you may still find it valuable to review their guidance documents. Alternately, reviews may adhere to reporting standards, such as PRISMA or MOOSE. Many of these guidelines have additional guidance on specific review content, such as Cochrane's section on systematic reviews on patient-reported outcomes or JBI's section on Systematic reviews of qualitative evidence.