It is our hope that this document will serve several useful purposes. Our primary goal is to improve patient care. We hope to accomplish this, in the short term, by helping clinicians know and better understand the evidence (or lack of evidence) that determines current practice. By providing comprehensive evidence-based recommendations, this guideline will also help define areas where evidence is lacking and research is needed. Helping to define a research agenda is an often neglected, but very important, function of clinical practice guideline development.
We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to rate the quality of evidence and the strength of recommendations. In all, there were 12 (17.1%) recommendations in this guideline for which the overall quality of evidence was graded ‘A,' whereas 36 (51.4%) were graded ‘B,' 17 (24.3%) were graded ‘C,' and 5 (7.1%) were graded ‘D.' Although there are reasons other than quality of evidence to make a grade 1 or 2 recommendation, in general, there is a correlation between the quality of overall evidence and the strength of the recommendation. Thus, there were 43 (62.3%) recommendations graded ‘1' and 26 (37.7%) graded ‘2.' There were 9 (13.0%) recommendations graded ‘1A,' 23 (33.3%) were ‘1B,' 10 (14.5%) were ‘1C,' and 1 (1.4%) was ‘1D.' There were 2 (2.9%) recommendations graded ‘2A,' 13 (18.8%) were ‘2B,' 7 (10.1%) were ‘2C,' and 4 (5.8%) were ‘2D.' There were 41 (37.3%) statements that were not graded.
Some argue that recommendations should not be made when evidence is weak. However, clinicians still need to make decisions in their daily practice, and they often ask, “What do the experts do in this setting?” We opted to give guidance, rather than remain silent. These recommendations are often rated with a low strength of recommendation and a low quality of evidence, or were not graded. It is important for the users of this guideline to be cognizant of this (see Notice). In every case these recommendations are meant to be a place for clinicians to start, not stop, their inquiries into specific management questions pertinent to the patients they see in daily practice.
We wish to thank the Work Group Co-Chairs, Drs. Adeera Levin and Paul Stevens, along with all of the Work Group members who volunteered countless hours of their time developing this guideline. We also thank the Evidence Review Team members and staff of the National Kidney Foundation who made this project possible. Finally, we owe a special debt of gratitude to the many KDIGO Board members and individuals who volunteered time reviewing the guideline, and making very helpful suggestions.
Bertram L Kasiske, MD KDIGO Co-Chair
David C Wheeler, MD, FRCP KDIGO Co-Chair