logo-network logo-network2 pixel-outer pixel

Synthesising the data

Synthesis is a stage in the systematic review process where extracted data, that is the findings of individual studies, are combined and evaluated.  

The general purpose of extracting and synthesising data is to show the outcomes and effects of various studies, and to identify issues with methodology and quality. This means that your synthesis might reveal several elements, including: 

  • overall level of evidence 
  • the degree of consistency in the findings 
  • what the positive effects of a drug or treatment are, and what these effects are based on 
  • how many studies found a relationship or association between two components, e.g. the impact of disability-assistance animals on the psychological health of workplaces

There are two commonly accepted methods of synthesis in systematic reviews: 

  1. Qualitative data synthesis
  2. Quantitative data synthesis (i.e. meta-analysis) 

The way the data is extracted from your studies, then synthesised and presented, depends on the type of data being handled. 

Qualitative data synthesis

If you have qualitative information, some of the more common tools used to summarise data include: 

  • textual descriptions, i.e. written words 
  • thematic or content analysis

Quantitative data synthesis, commonly referred to as meta-analysis

If you have quantitative information, some of the more common tools used to summarise data include: 

  • grouping of similar data, i.e. presenting the results in tables 
  • charts, e.g. pie-charts 
  • graphical displays, i.e. forest plots


Print Friendly, PDF & Email