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Systematic Review: Case Study - Synthesis

Synthesis

​Cari and Lee have already decided that their study will be a meta-synthesis, as they don’t have the skill or time to conduct a full-scale quantitative meta-analysis. The meta-synthesis approach means that they will focus on the results presented in their included articles to identify any trends or patterns. To do this, they first generate a summary table noting the main properties of their studies. They start with general headings: Author/year, method, results, conclusions, and gradually add more specific columns as they make notes on their articles. Some of the additional columns relate to aspects of the articles’ sampling and intervention processes, as well as identifying the outcome measures considered. 

They note that for a few of the studies, they need to draw their own conclusions based on specific results (e.g. some studies compare polyphenol-fortified chocolate with standard chocolate. In these cases, they look only at the standard results). 


An extract of the table looks like:

 

Synthesis

Cari and Lee now use the table to help them answer some questions: 

  • What is the link between chocolate/cocoa consumption and cholesterol levels?
  • Are the results consistent across all the studies?
  • If not, can the results be explained by another factor, e.g.:
    • Sample properties, such as baseline cholesterol levels, type of obesity, sex or age.
    • Is there any trend with time (age of study, or study duration) or location?
    • Is there any trend with study quality?
      • Do lower-quality studies agree with high-quality studies?

And importantly, can Cari and Lee now answer their initial research question: 

 

In people at risk of cardiometabolic disorders (Pop) whose weight is classified as obese (Prob), how effectively does chocolate (I) reduce cholesterol level (O)?

 

The answers to these questions will form the basis of the discussion section of Cari and Lee’s systematic review article. 

Now, they are ready to write up their research and submit it for publication.