Critical Appraisal

What is critical appraisal?
Systematic evaluation of the evidence for accuracy, relevance and validity; eliminating research that isn’t relevant or robust enough for the question you are asking

Why is it important?
Much of the research, although methodologically valid, will not be clinically relevant and valid for your research purposes.

How do you critically appraise an article?
In addition to asking questions about author credentials, journal publication and date, there are some very useful tools to help you establish the relevance, accuracy and validity of the research.

elearning for healthcare (eLfH) have developed a series of Critical Appraising the Evidence Base sessions which take about 30 minutes each. Register for eLfH or access the course via ESR to evidence your learning (NHS staff only)

CASP-UK  has eight checklists of questions designed to quickly evaluate your chosen article including:

Systematic Reviews
Case Study
Control Study
Clinical Prediction Rule

RCTs How to critically appraise a randomised controlled trial (RCT) using the CASP checklist Barts Health Knowledge and Library Services’ developed a series of bite-sized videos using the CASP tool

Videos with links to relevant CASP checklist and quiz were developed by Cochrane Common Mental Disorders, Northumberland, Tyne and Wear NHS Foundation Trust (NTW) and Tees, Esk and Wear Valleys NHS Foundation Trust (TEWV).

  1. Introduction to critical appraisal
  2. Systematic reviews & meta-analysis
  3. Randomised controlled trials
  4. Cohort studies
  5. Case control studies
  6. Cross-sectional studies
  7. Diagnostic studies

CEBM has tools for evaluating RCTs, systematic reviews and diagnostics. It also contains calculators for checking statistics, the all-purpose 2×2 table, probabilities and confidence intervals

Useful books in the library include:

Bootland, D et al. Critical appraisal from papers to patients: a practical guide. CRC Press. 2017

Crombie IK The pocket guide to critical appraisal: a handbook for health care professionals 2nd ed. 2023 Wiley

Greenhalgh T. How to read a paper: the basics of evidence-based medicine.  6th ed. 2019. John Wiley

Issa M. Critical appraisal made easy: evidence based medicine. 2018 PBG Group

ClinicalKey has several books with chapters on Critical appraisal and evaluating the statistics

Raine R & Barrett H Evidence-based practice. In Kumar and Clark’s Clinical Medicine 10th ed. 2021 Elsevier

Schumacher KR., McCrindle BW & Pasquali SK Description and analysis of data, and critical appraisal of the literature. In Anderson’s Pediatric cardiology. 4th ed. 2020 Elsevier