Critical Appraisal Guide: Critical Appraisal Guide

Critical appraisal is the assessment of evidence by systematically reviewing its relevance, validity and results to specific situations.

The CASP (Critical Skills Appraisal Programme) website has a useful range of free downloadable resources which can help you structure your research strategy and help you shape your research criteria. The CASP Checklists can help you determine which studies to focus on and which match the criteria you have laid out for your systematic review. The critical appraisal tools are designed to be used when reading research and include the following:

• Systematic Reviews
• Randomised Controlled Trials
• Cohort Studies, Case Control Studies
• Economic Evaluations
• Diagnostic Studies
• Qualitative studies
• Clinical Prediction Rule

Mixed Methods Tools

• Mixed methods appraisal tool (MATT)
• Evaluation Tool for 'Mixed Methods' Study Designs 

(e-Resources by the University of Nottingham)

• Confidence levels - an introduction
• Determining the clinical importance of trial results
• Numbers needed to treat (NNT) and numbers needed to harm (NNH)
• Relative risk reduction (RRR) and absolute risk reduction (ARR)

These links will direct you to further sources of critical appraisal help

• AGREE- Appraisal of guidelines for research and evaluation
• Bandolier - "Evidence based thinking about healthcare"
• BestBETS Critical appraisal worksheets
• CEMB critical appraisal sheets (Centre for Evidence Based Medicine)
• Critical appraisal of clinical trials (Medicines Learning Portal)
• Finding and appraising the evidence (online tutorial by Health Knowledge)
• Students 4 best evidence - student network with simple explanations of difficult concepts

This video presentation from Dr Andrew Booth at ScHARR, University of Sheffield, talks you through the process of critically reading a qualitative study/research paper, using the CASP checklist, with on-screen analysis and highlighting of text.