Skip to Main Content

Study Design Basics

How do I evaluate studies?

This evaluation of evidence is commonly known as critical appraisal and is intended to result in a better understanding of the significance of a study's findings.

Click on the flipcards below to learn about three important factors of critical appraisal:

Internal validity or trustworthiness
Was the study methodologically sound?
How important are the study's findings?
External validity or applicability
Are the results of the study applicable to other populations or settings?

Critical appraisal tools

To make the process of critical appraisal easier, critical appraisal tools or checklists have been developed. These guide the appraiser through the process in an efficient yet comprehensive manner.

There are many different critical appraisal tools. Determining which to use comes down to finding one that:

  • fits best with the study you are appraising
  • is reliable, well-known or otherwise validated
  • you understand and are comfortable using

Below are some trusted providers of critical appraisal tools:

  • CASP (Critical Appraisal Skills Programme)
  • JBI (Joanna Briggs Institute)
  • CEBM (Centre for Evidence-Based Medicine)
  • SIGN (Scottish Intercollegiate Guidelines Network)
  • BMJ Best Practice (British Medical Journal)