Critical appraisal is a key component of systematic review methodology; it is optional in scoping reviews. Critical appraisal involves evaluating the risk of bias and certainty of the evidence of studies included in the review. Assessment is based on criteria such as the clarity of the research question, study design and methods, data analysis, and reporting.

There are many critical appraisal tools to assist in the process. Be sure to choose a tool appropriate to the study design you are appraising.

Two reviewers should carry out independent appraisal of the studies, and it is advisable to have two or more reviewers test the proposed tool prior to completing appraisal of the studies.

Critical Appraisal Tools
You can find critical appraisal tools at the following sites. Remember to choose a tool appropriate to the study design you are appraising.

• JBI Critical Appraisal Tools
• CASP Checklists
• Quality Assessment and Risk of Bias Tool Repository
• Centre for Evidence Based Medicine (CEBM) Critical Appraisal Tools
• Systematic Review Toolbox (under Advanced Search, select "Guidance" and "Quality Assessment")