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Evidence-Based Practice: Grading Evidence

Evidence-Based Practice Help Guide

Grading Evidence used in a Policy or Guideline

Clinical guidelines and procedures should be based on the best available evidence if it exists. Choosing the best study type to answer your question will assist you in finding the best evidence. 

The hierarchy pyramid for Primary Research :

Adapted from  NHMRC levels of evidence and grades for recommendations 2009


Level 1 evidence represents the gold standard for intervention studies. For some guidelines it may be appropriate to utilise results from studies with lower levels of evidence. Some clinical guidelines may also be informed by expert opinion in the field from within the Department of Health or nationally/internationally from journal articles. 

Once you have decided which articles best answer your question (See Finding the Evidence) you will then need to critically appraise the research. Some tools to help you with this can be found at 

There are various frameworks available to grade the quality of evidence for making a recommendation thus providing a level of transparency for the guideline or procedure being developed:

Tutorials on Grading Evidence

Need more help?

NHMRC Guidelines for Guidelines

Clinical Librarians can provide advice on the literature used in guideline development.

They can also assist with:

  • how to find the evidence and the resources available to critically appraise studies. 
  •  find the research evidence utilising Library resources: such as  Cochrane Library, UpToDate, Medline and CINAHL (either through training or providing a literature search)
  •  one to one, group or online training in searching

To place a request for assistance,  email and one of our staff will get back in touch with you. Alternatively you can call the Health Library on 89228961.