After identifying relevant studies for a synthesis, reviewers may critically appraise the validity of these studies in order to determine the risk of bias and how to use this information in any data synthesis.
Grant and Booth (2009) provide a typology of review types that specifically indicates whether or not critical appraisal is generally a component of 14 different reviews types:
Table 1: Main review types characterized by methods used
For more information about critical appraisal:
Tools for assessing quality and risk of bias in the Cochrane Handbook for Systematic Reviews of Interventions (Section 8.3)
The institutions and organizations below provide useful tools and checklists for the critical appraisal of different types of studies.
Critical appraisal tools from: