Literature Appraisal Skills

Literature Appraisal Skills

What is a Literature Search?

This is a systematic, organised search of the research papers published on a particular topic. A well-structured literature search is the most effective and efficient way to locate reliable evidence on a research topic.

When you have sourced your relevant journal articles to answer a clinical question, you require the ability to critically appraise them.

What is Critical Appraisal?

Critical appraisal of a journal article is a literary and scientific systematic dissection in an attempt to assign merit to the conclusions of an article.

Critical appraisal of scientific literature is a necessary skill for healthcare professionals as part of their professional obligation and CPD commitment. This leads to progression of skills linked to a sound knowledge base, as they navigate along their specific career journey.

Signpost: Database searching is a skill in itself, check out References + Resources

Ideally, an article will be able to undergo scrutiny using critical thinking skills to evaluate the findings as valid.

What is Reliability + Validity?

In the clinical setting, making evidence-based decisions requires methods that are accurate, reliable and valid. Accuracy is where the result of a measurement equates to the correct value that is precise.

Reliability is a measure of the repeatability of the activity.

Repeatability will be affected by;

  • Inter repeatability which looks at the reliability of different therapists carrying out the same activity at different times
  • Intra repeatability examines the reliability of the testing carried out by the same therapist at different times

Validity is a measure of how sound the research is and more specifically, validity applies to both the design and the methods used. Validity is internal and external and these reflect whether or not the results of a study are trustworthy and meaningful. Whilst internal validity relates to how well a study is conducted (its structure), external validity relates to how applicable the findings are to clinical practice.

When making statements, it's important that the statement is both reliable and valid and not an opinion.

The specific questions used to assess validity change slightly with different study designs and article types. Use the questions below as a quick reference to appraise any journal article.

The first 4 checklist questions should be answered “YES.” If any of the 4 questions are answered “NO” then you should return to your search and attempt to find an article that will meet these criteria.

Critical Appraisal Skills


  1. Does the article attempt to answer the same question as your clinical question?
  2. Is the article recently published (within 5 years) or is it seminal (i.e. an earlier article but which has strongly influenced later developments)?
  3. Is the journal peer-reviewed?
  4. Do the authors present a hypothesis?

The Methods

  1. Is the study design valid for your question?
  2. Are both inclusion and exclusion criteria described?
  3. Is there an attempt to limit bias in the selection of participant groups?
  4. Are there methodological protocols (i.e. blinding) used to limit other possible bias?
  5. Do the research methods limit the influence of confounding variables?
  6. Are the outcome measures valid for the health condition you are researching?

The Results

  1. Is there a table that describes the subjects’ demographics?
  2. Are the baseline demographics between groups similar?
  3. Are the subjects generalizable to your patient?
  4. Are the statistical tests appropriate for the study design and clinical question?
  5. Are the results presented within the paper?
  6. Are the results statistically significant and how large is the difference between groups?
  7. Is there evidence of significance fishing (i.e. changing statistical tests to ensure significance)?

The Discussion / Conclusion

  1. Do the authors attempt to contextualise non-significant data in an attempt to portray significance? (i.e. talking about findings which had a trend towards significance as if they were significant).
  2. Do the authors acknowledge limitations in the article?
  3. Are there any conflicts of interests noted?

This is a starter pack to using critical thinking skills when appraising a scientific journal article. By answering the questions above, after you have read the article, you can then appraise it's merit and determine whether the results are valid.

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