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Unit 5. Grade the evidence

How to grade the evidence

Clinicians, researchers, decision-makers and the general population need guidance and information to decide how much confidence to place in a recommendation derived from the biomedical literature. This is a vital step also when developing recommendations for clinical practice guidelines.

Confidence in the findings of a study may be limited for a number of reasons, mainly related to systematic error or “bias”. Several methods and scales have been developed to address how to grade the quality of published evidence. Sadly the result was the lack of a common language, lack of agreement and the built of a new “Babel tower”.