Article type
Year
Abstract
Background: Cochrane has adopted the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to categorizing quality of evidence - most prominently seen in 'Summary of 'indings' tables – defined as reflecting the extent of confidence that the estimates of effects are correct. This definition leaves ambiguity: does it refer to confidence in point estimates, or confidence in the range of possible estimates?
Objective: To clarify the definition and approaches to judging evidence quality.
Method: Discussions, workshops, iterative refinement of ideas, and discussion at a GRADE Working Group meeting.
Results: Based on this process, quality of evidence may be better considered as the confidence or certainty that a true effect lies on one side of a specified threshold, or within a chosen range.
This interpretation raises the challenge of defining the threshold or range for making quality ratings. We developed five possible approaches for making this judgment. For guidelines, what we call a fully contextualized approach requires simultaneously considering all critical outcomes and their relative value. We defined four less contextualized approaches more appropriate for systematic reviews. We applied all five approaches to the outcome of myocardial infarction in a review of dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT) in patients who have undergone stenting of their coronary arteries (Table).
The four approaches most appropriate for systematic reviews involve judging certainty that the true effect lies within the 95% confidence interval; that the effect lies within some range other than the 95% confidence interval; that the effect is something other than no effect at all; and that the effect lies within ranges of what we might consider small, moderate, or large.
Conclusions: The proposed approach is now under consideration by the GRADE Working Group. If adopted by GRADE, and subsequently by Cochrane, it will provide a useful clarification of how Cochrane authors can make quality of evidence judgments.
Objective: To clarify the definition and approaches to judging evidence quality.
Method: Discussions, workshops, iterative refinement of ideas, and discussion at a GRADE Working Group meeting.
Results: Based on this process, quality of evidence may be better considered as the confidence or certainty that a true effect lies on one side of a specified threshold, or within a chosen range.
This interpretation raises the challenge of defining the threshold or range for making quality ratings. We developed five possible approaches for making this judgment. For guidelines, what we call a fully contextualized approach requires simultaneously considering all critical outcomes and their relative value. We defined four less contextualized approaches more appropriate for systematic reviews. We applied all five approaches to the outcome of myocardial infarction in a review of dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT) in patients who have undergone stenting of their coronary arteries (Table).
The four approaches most appropriate for systematic reviews involve judging certainty that the true effect lies within the 95% confidence interval; that the effect lies within some range other than the 95% confidence interval; that the effect is something other than no effect at all; and that the effect lies within ranges of what we might consider small, moderate, or large.
Conclusions: The proposed approach is now under consideration by the GRADE Working Group. If adopted by GRADE, and subsequently by Cochrane, it will provide a useful clarification of how Cochrane authors can make quality of evidence judgments.