Systematic Review Toolbox

Data Analysis

Analyzing data and interpreting results of a systematic review and/or meta-analysis can be intimidating at first due to the sheer volume of information. However, the task is manageable if a methodical way is employed. To formulate a synthesis of findings from multiple qualitative studies (often called a narrative synthesis), simply collect the major findings of all included studies by study type, and determine if the collection alludes to positive, negative, mixed, or inconclusive results by frequency of findings. The CCACE states: "If studies are very heterogenous it may be most appropriate to summarise the data narratively and not attempt a statistical (meta-analytic) summary."

Quantitative studies of similar quality and methodology can be analyzed, compared, and aggregated using the tools of meta-analysis. Calculators in systematic review manuscript development tools (e.g., RevMan) are often employed, but Excel templates can be used as well. The Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh (CCACE) adds that "a statistical synthesis should include numerical and graphical presentations of the data, and also look at the strength and consistency of the evidence, and investigate reasons for any inconsistencies." More detailed information on meta-analytic summations or statistical synthesis can be found here.

Following Cochrane review guidelines for planning and conducting data analyses in systematic reviews is another authoritative source on the subject.