Critical appraisal

The purpose of the current article is to define critical appraisal, identify its benefits, discuss conceptual issues influencing the adequacy of a critical appraisal, and detail procedures to help reviewers undertake critical appraisals. A critical appraisal involves a careful and systematic assessment of a study’s trustworthiness or methodological rigour, and contributes to assessing how confident people can be in the findings of a set of studies. To help reviewers include high quality critical appraisals in their articles, they can consider differences between quality and bias, the value of total quality scores, the advantages and disadvantages of standardized checklists, the relevance of the experimental hierarchy of evidence, the differences between critical appraisal tools and reporting standards, and the challenges involved in appraising qualitative research. The steps involved in a sound critical appraisal include: (a) identifying the study type(s) of the individual paper(s), (b) identifying appropriate criteria and checklist(s), (c) selecting an appropriate set of criteria and checklist, (d) performing the appraisal, and (e) summarizing and using the results. Although these steps apply to critical appraisals of both quantitative and qualitative research, they require reviewers to make and defend a number of decisions resulting from the subjective features involved in assessing research.