GRADE Series - Sharon Straus, Rachel Churchill and Sasha Shepperd, Guest Editors| Volume 64, ISSUE 12, P1311-1316, December 01, 2011

GRADE guidelines: 9. Rating up the quality of evidence

      Abstract

      The most common reason for rating up the quality of evidence is a large effect. GRADE suggests considering rating up quality of evidence one level when methodologically rigorous observational studies show at least a two-fold reduction or increase in risk, and rating up two levels for at least a five-fold reduction or increase in risk. Systematic review authors and guideline developers may also consider rating up quality of evidence when a dose–response gradient is present, and when all plausible confounders or biases would decrease an apparent treatment effect, or would create a spurious effect when results suggest no effect. Other considerations include the rapidity of the response, the underlying trajectory of the condition, and indirect evidence.

      Keywords

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