We also searched for pertinent existing guidelines and systematic reviews. grading criteria Describe the criteria used to rate the quality of evidence that supports the recommendations and the system for describing the strength of the recommendations. Recommendation strength communicates the importance of adherence to a recommendation and is based on both the quality of the evidence and the magnitude of anticipated benefits and harms. Quality of individual studies was graded in a three-tiered grading system (see Table 10). Quality of evidence and strength of recommendations were graded following the GRADE approach (Tables 12 and 14). The Work Group could provide general guidance in unngraded statements. 10. Method for synthesizing evidence Describe how evidence was used to create recommendations, e.g., evidence tables, meta-analysis, decision analysis. For systematic review topics, summary tables and evidence profiles were generated. For recommendations on treatment interventions, the steps outlined by GRADE were followed. 11. Prerelease review Describe how the guideline developer reviewed and/or tested the guidelines prior to release. The guideline had undergone internal review at the 2010 KDIGO Board of Directors meeting and external public review in July 2011. Public review comments were compiled and fed back to the Work Group, which considered comments in its revision of the guideline. 12. Update plan State whether or not there is a plan to update the guideline and, if applicable, an expiration date for this version of the guideline. There is no date set for updating. The need for updating of the guideline will depend on the publication of new evidence that would change the quality of the evidence or the estimates for the benefits and harms. Results from registered ongoing studies and other publications will be reviewed periodically to evaluate their potential to impact on the recommendations in this guideline. 