c Sparse if there is only one study or if total N o500. Imprecise if there is a low event rate (0 or 1 event) in either arm or confidence interval spanning a range 41. Adapted by permission from Macmillan Publishers Ltd, Kidney International. Uhlig K, Macleod A, Craig J et al. Grading evidence and recommendations for clinical practice guidelines in nephrology. A position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int 2006; 70: 2058 2065;157 accessed http://www.nature.com/ki/journal/v70/n12/pdf/5001875a.pdf. methods for guideline development grade of an individual outcome could not exceed the quality grade for the overall study. Grading the quality of evidence and the strength of a guideline recommendation A structured approach, based on Grading of Recom- mendations Assessment, Development and Evaluation and facilitated by the use of evidence profiles was used to grade the quality of the overall evidence and the strength of recommendations. For each topic, the discussion on grading of the quality of the evidence was led by the ERT, and the discussion regarding the strength of the recommendations was led by the Work Group Co-Chairs. The strength of a recommendation indicates the extent to which one can be confident that adherence to the recommendation will do more good than harm. The quality of a body of evidence refers to the extent to which our confidence in an estimate of effect is sufficient to support a particular recommendation.445 Grading the quality of evidence for each outcome across studies. 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. 