Following GRADE, the quality of a body of evidence pertaining to a particular outcome of interest was initially categorized on the basis of study design. For questions of interventions, the initial quality grade was High if the body of evidence consisted of RCTs, Low if it consisted of observational studies, and Very Low if it consisted of studies of other study designs. For questions of interventions, the Work Group decided to use only RCTs. The grade for the quality of evidence for each intervention outcome pair was then lowered if there were serious limitations to the methodological quality of the aggregate of studies, if there were important inconsistencies in the results across studies, if there was uncertainty about the directness of evidence including limited applicability of the findings to the population of interest, if the data were imprecise (a low event rate in either arm or a CI spanning a range 41) or sparse (only 1 study or total No500), or if there was thought to be a high likelihood of bias. The final grade for the quality of the evidence for an intervention outcome pair could be one of the following four grades: High , Moderate , Low or Very Low (Table 11). Grading the overall quality of evidence. The quality of the overall body of evidence was then determined on the basis of the quality grades for all outcomes of interest, taking into Table 14 | KDIGO nomenclature and description for grading recommendations Implications Grade* Patients Clinicians Policy We recommend Most people in your situation would want the recommended course of action and only a small proportion would not. Most patients should receive the recommended course of action. The recommendation can be evaluated as a candidate for developing a policy or a performance measure. 