Once screening (article selection) is completed, the Quality Assessment part of the systematic review process may begin. Quality assessment may be performed before or after data extraction.
Since systematic reviews rely on data from other studies, the evidence in a systematic review is only as good as, or as free from bias as, the included studies. Therefore, the methodological quality of each individual study included in a systematic review should be assessed. This process involves appraising, judging, and documenting potential risks of bias.
We recommend that you use Covidence to conduct quality assessment.
Each study design will be appraised using a separate tool. For help in deciding which risk of bias / quality assessment tool(s) to use for each study design, consult one of the following sites.