Systematic Reviews

Your collected data must be combined into a coherent whole and accompanied by an analysis that conveys a deeper understanding of the body of evidence. All reviews should include a qualitative synthesis, and may or may not include a quantitative synthesis (also known as a meta-analysis).

A qualitative synthesis is a narrative, textual approach to summarizing, analyzing, and assessing the body of evidence included in your review. It is a necessary part of all systematic reviews, even those with a focus on quantitative data.

Use the qualitative synthesis to:

• Provide a general summary of the characteristics and findings of the included studies.
• Analyze the relationships between studies, exploring patterns and investigating heterogeneity.
• Discuss the applicability of the body of evidence to the review's question within the PICO structure.
• Explain the meta-analysis (if one is conducted) and interpret and analyze the robustness of its results.
• Critique the strengths and weaknesses of the body of evidence as a whole, including a cumulative assessment of the risk of bias across studies.
• Discuss any gaps in the evidence, such as patient populations that have been inadequately studied or for whom results differ.
• Compare the review's findings with current conventional wisdom when appropriate.

A quantitative synthesis, or meta-analysis, uses statistical techniques to combine and analyze the results of multiple studies. The feasibility and sensibility of including a meta-analysis as part of your systematic review will depend on the data available.

Requirements for quantitative synthesis:

• Clinical and methodological similarity between compared studies
• Consistent study quality among compared studies
• Statistical expertise from a review team member or consultant