Special rates are available for educational institutions that wish to make photocopies for non-profit educational use. No part of this publication may be reproduced, amended, or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without explicit permission in writing from KDIGO. Details on how to seek permission for reproduction or translation, and further information about KDIGO s permissions policies can be obtained by contacting Danielle Green, Managing Director, at: danielle.green@kdigo.org To the fullest extent of the law, neither KDIGO, Kidney International Supplements, National Kidney Foundation (KDIGO s former Managing Agent) nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Foreword 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 guide- line 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 recommenda- tions. 