Data extraction in a systematic review is the process of systematically collecting and recording key information from the included studies. This typically includes study characteristics, methods, participants, interventions, outcomes, and results, to enable synthesis and analysis of the evidence.
Why is it important to extract data?
Ensures accuracy and consistency by collecting all relevant information systematically from each study.
Provides the structured data needed for narrative or quantitative analysis.
Allows others to see exactly what data were used and how conclusions were drawn.
Highlights where evidence is incomplete or inconsistent.
Reduces bias – standardised extraction by at least two reviewers minimises selective reporting or errors.
Provides the details needed to appraise study risk of bias or methodological quality.