A Systematic Review is a review of a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyse data from the included studies. Statistical methods (meta-analysis) may be used to analyse and summarise the results of the included studies. Meta-analysis refers to the use of statistical techniques in a review to integrate the results of included studies.¹

Systematic Reviews differ from traditional narrative reviews and the key characteristics of a systematic review are:

• a clearly stated set of objectives with pre-defined eligibility criteria for studies
• an explicit, reproducible methodology
• a systematic search that attempts to identify all studies that would meet the eligibility criteria
• an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias and
• a systematic presentation, and synthesis, of the characteristics and findings of the included studies.

Steps of a Systematic Review

The Need for Systematic Reviews

Systematic Reviews are the "gold standard" for synthesising evidence in health because of their rigorous methodology.  They are an important source of evidence to guide the development of clinical practice guidelines and to inform clinical decision-making. More generally Systematic Reviews provide healthcare professionals, consumers, researchers, and policy makers with identified, appraised, and synthesised research-based evidence in an accessible format, therefore saving them considerable time.²

References

1. Higgins, P.T., & Green, S. (eds.). (2008). Cochrane handbook for systematic reviews of interventions.  Chichester, England ; Hoboken, NJ : Wiley- Blackwell.  Available: http://handbook.cochrane.org/

2. Mulrow, C.D. (1994). Rationale for systematic reviews. BMJ 309: 597-599. Available: http://www.ncbi.nlm.nih.gov/pubmed/8086953

Covidence has developed a step-by-step guide on how to complete Systematic Reviews. Click on this link to download the handout. 

For more detailed instruction on Conducting a Systematic Review see the Cochrane Handbook for Systematic Reviews of Interventions.  The latest (Version 6, 2019) edition of the Cochrane Handbook is available here.