1. Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital of Münster, Münster, Germany and Outcomes Research Consortium , Cleveland, OH , USA
2. Section of Nephrology, Department of Medicine, University of Chicago , Chicago, IL , USA
3. Program for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh , Pittsburgh, PA , USA
4. Department Intensive Care Medicine, Radboud University Medical Centre , Nijmegen , The Netherlands
5. Department of Critical Care, Royal Surrey Hospital Foundation Trust , Guildford, UK
6. Faculty of Health Sciences, University of Surrey , Guildford, UK