According to Amanda Burls, critical appraisal is the examination of research studies to determine whether their results are valid and are relevant within a particular context. It is essential that when researchers examine the literature they can see that the study has been executed properly, that the results make sense, and that the results will have meaning for them when making decisions. (1)
Some of the standard questions asked when critically appraising the literature include: (2)
What is the research question?
What is the study type (design)?
Selection issues.
What are the outcome factors and how are they measured?
What are the study factors and how are they measured?
What important potential confounders are considered?
What is the statistical method used in the study?
Statistical results.
What conclusions did the authors reach about the research question?
Are ethical issues considered?
Sources:
1. Burls A. What is critical appraisal? London: Hayward Medical Communications; 2009 http://www.bandolier.org.uk/painres/download/What%20is%202009/What_is_crit_appr.pdf
2. Al-Jundi A, Sakka S. Critical Appraisal of Clinical Research. J Clin Diagn Res. 2017 May;11(5):JE01-JE05. doi: 10.7860/JCDR/2017/26047.9942. Epub 2017 May 1. PMID: 28658805; PMCID: PMC5483707.
When conducting a critical appraisal of the literature, the best approach is to employ a standardized method. Below are some appraisal tools that have been developed for specific study designs.
Adapted from:
Mayo Clinic Library Systematic Review Guide
AXIS A tool to assess the quality of cross-sectional studies
CEBM Assessing Qualitative Studies worksheet
CASP Qualitative Studies checklist
JBI Tools for assessing the quality of non-randomized studies
MINORS Methodological index for non-randomized studies
Newcastle-Ottawa Scale (NOS) Tool for assessing quality of non-randomized studies
ROBINS E Risk Of Bias In Non-randomized Studies - of Exposures
ROBINS I Risk of Bias on Non-Randomized Studies - of Interventions