Throughout the project, the ERT offered suggestions for guideline development and led discussions on systematic review, literature searches, data extraction, assessment of quality and applicability of articles, evidence synthesis, grading of evidence and guideline recommendations, and consensus development. The Work Group took the primary role of writing the recommendation statements and rationale and retained final responsibility for their content. The Work Group Co-Chairs prepared the first draft of the scope of work document as a series of open-ended questions to be considered by Work Group members. At their first 2-day meeting, members added further questions until the methods for guideline development http://www.kidney-international.org & 2012 KDIGO initial working document included all topics of interest to the Work Group. The inclusive, combined set of questions formed the basis for the deliberation and discussion that followed. The Work Group strove to ensure that all topics deemed clinically relevant and worthy of review were identified and addressed. Formulating questions of interest Questions of interest were formulated according to the PICODD (Population, Intervention, Comparator, Outcome, study Design and Duration of follow-up) criteria. Details of the criteria are presented in Table 5. Ranking of outcomes The Work Group ranked outcomes of interest on the basis of their importance for informing clinical decision making (Table 6). Doubling of SCr level or halving of GFR was upgraded from high to critical importance in studies where (or the SCr was 42 mg/dl [4177 mmol/l]), given the known adverse con- sequences of advanced CKD. 