At this stage, you will develop your evidence tables, which give detailed information for each study (see Table 1 in this article). You can create evidence tables to describe study characteristics, results, or both.
Data extraction requires a lot of planning. We will review some of the tools you can use for data extraction, the types of information you will want to extract.
What data you extract will depend on your research question and the needs of your review.
Helpful data for an intervention question may include:
If you are doing a qualitative review, you may want to extract data on the theoretical framework, data collection method, and role of researcher and their potential bias.
Individual studies are evaluated for potential bias, based on study design and reporting. When conducting a systematic review, at least one critical appraisal tool should be chosen, a priori, to evaluate the studies.
Consult the following article for general information on risk of bias assessment.
|Study Type||JBI Critical Appraisal Tools||CASP: Critical Appraisal Checklists||LEGEND Evidence Evaluation Tools||Risk of Bias Tools (formerly Cochrane Risk of Bias Tools)||Quality assessment tool for quantitative studies (EPHPP)||SIGN Checklists||
(Used with other tools to evaluate intervention outcomes)
|AGREE II||AMSTAR 2|
|Randomized Controlled Trials (RCTs)||X||X||X||X||X||X||X||X|
|Systematic Reviews and Meta-Analyses||X||X||X||X||X||X||X|
|Clinical Practice Guidelines||X||X|
|Other Study Designs||X||X|
The following were consulted for this table. Please consult these resources to find: evaluations of many of these tools, appraisal tools focused on other study designs, and additional critical appraisal tools.
While librarians do not provide assistance with statistics, the Biostatistics and Health Data Science offers assistance.