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Critical Appraisal

Information and resources on how to assess the quality and relevance of articles



BMJ How to read a paper. A series of papers on how to read and critique different types of research articles.

BMJ Statistical notes series. A series of explanatory notes on interpreting statistics in medical research. Topics include validating scales, correlation, probabilities, bootstrap resampling and many more. To access full text, go to  Find an article for your institution at the library webpage, then enter 'Statistics notes'.

University of Nottingham - making sense of the numbers (AudioVisual series)

Confidence intervals 

Numbers needed to treat and numbers needed to harm 

Relative risk reduction and absolute risk reduction 

Sensitivity and Specificity 

Surrogate Outcomes

Determining the clinical importance of trial results


Critical Appraisal Tools

Critical Appraisal Study Programme (CASP) – Free checklists to be used when reading research. Eight versions are available to assist in evaluating different study types.

University of Glasgow General Practice and Primary Care EBP checklists

Oxford Centre for Evidence-Based Medicine (CEBM) - Critical Appraisal Tools. A variety of resources, including in languages other than English.

Joanna Briggs Institute  - Critical Appraisal Tools. Free checklists and notes from a leading authority on using evidence to support decision making.

University of South Australia, International Centre for Allied Health Evidence – appraisal tools 



Catalogue of bias - descriptions of biases that can affect studies and strategies to prevent bias occurring. Supported by Oxford CEBM

Identifying and Avoiding Bias in Research - article



How to Use the Evidence. Handbook on how to use research evidence when preparing clinical guidelines (PDF). National Health and Medical Research Council, 2000.