Critical appraisal evaluates evidence for its:

• relevance (are the findings relevant to the patient/population of interest?)
• validity (e.g. has bias been minimised?)
• results (what were the findings of the study?)

This is achieved through careful examination and evaluation of the evidence. Take a look at some of the tools/guides available to assist with this process.

Criticial appraisal is an essential skill in Evidence-Based Practice (see the Evidence Based Practice guide for more information).

[Adapted from La Trobe University]

Even articles published in peer-reviewed journals may still have issues with methodology, reports or conclusions drawn. Critical appraisal enables assessment of these results, relevance and validity of published papers so that a decision can be made about the authority of research and applicability to the local population.

Critical appraisal skills promote understanding of:

• which treatments or interventions may really work;
• whether research has been conducted properly and has been reported reliably;
• which services or treatments are potentially worth funding;
• whether the benefits of an intervention are likely to outweigh the harms or costs;
• what to believe when making decisions when there is conflicting research.

[Adapted from CASP]

These are some questions you may ask:

• Look for a research problem (usually in the abstract, title or introduction)
• What is the purpose? Check the abstract
• Does it have a bias?
• What are the authors' affiliations?
• Is it a literature review?
• Is it a hypothesis or research question?
• Who funded the research?
• What is the sample or population interest?
• What is the type of research or study?
• Benefits versus harm/costs?
• Important outcomes/findings?

Checklists assist in learning to critically appraise medical research and are available for a range of study designs.

• The Critical Appraisal Skills Programme (CASP) is part of Better Value Healthcare, a training organisation led by Professor Sir Muir Gray, and based in Oxford. It is best known for its checklists, a set of eight critical appraisal tools designed to be used when reading research.
• The OT seeker includes a critical appraisal tutorial from a team of occupational therapists from two major Australian universities.
•  JBI EBP (Joanna Briggs Institute Evidence-Based Practice) comprises of checklists of questions for use in assessing 13 types of research study (including qualitative research and ramdomised controlled trails).