What is the GRADE methodology and how is it used to determine the overall quality of evidence for a recommendation?
The GRADE methodology is a systematic approach to assessing the quality of evidence, including the confidence in the effect estimates of the available studies. This approach is used to determine the overall quality of evidence for a recommendation. The evidence review used for the development of recommendations, conducted by ECRI, assesses the confidence in the quality of the evidence base using GRADE methodology and assigns a rating of High, Moderate, Low, or Very Low. The outcomes judged to be critical are used to determine the overall quality of evidence. Per GRADE, if the quality of evidence differs across the critical outcomes, the lowest quality of evidence for any of the relevant critical outcomes determines the overall quality of the evidence for a recommendation; the overall confidence cannot be higher than the lowest confidence in effect estimates for any outcome that is determined to be critical for clinical decision making.