What is the GRADE estimation system for assessing the quality of evidence for an intervention outcome pair?
The GRADE system is a system used to assess the quality of evidence for an intervention outcome pair. It initially categorizes the initial quality grade based on study design, with High quality being assigned to randomized controlled trials (RCTs), Low quality being assigned to observational studies, and Very Low quality being assigned to studies of other designs. The grade may further be lowered if there are serious methodological limitations, important inconsistencies in the results across studies, uncertainty about the evidence, imprecise or sparse data, or a high likelihood of bias. The final grade for the quality of evidence can be one of four grades: High, Moderate, Low, or Very Low.