Table 3| Classi cation for certainty and quality of the evidence Grade Quality of evidence Meaning A High We are con dent that the true effect is close to the estimate of the effect. B Moderate The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. C Low The true effect may be substantially different from the estimate of the effect. D Very low The estimate of effect is very uncertain, and often it will be far from the true effect. methods for guideline development www.kidney-international.org summary of the evidence quality in support of the recommendations. Grading the strength of the recommendations. The strength of a recommendation is graded as strong or weak (Table 5). The strength of a recommendation was determined by the balance of bene ts and harms across all critical and important outcomes, the grading of the overall quality of evidence, patient preferences and values, resources, and other considerations (Table 6). Balance of bene ts and harms. The Work Group and ERT determined the anticipated net health bene t on the basis of expected bene ts and harms across all critical and important out- comes from the underlying evidence review. In addition to the evi- dence review, the ERT assisted Work Group members in evaluating the balance of bene ts and harms arising from key individual studies. The overall quality of evidence. The overall quality of the evidence was based on the certainty of the evidence for all critical and important outcomes, taking into account the relative importance of each outcome to the population of interest. The overall quality of the evidence was graded A, B, C, or D (Table 3). 