1. Kaiser Permanente Center for Health Research, Portland, Oregon, USA.
2. Global Medical Affairs, Boehringer Ingelheim International GmbH, Ingelheim, Germany.
3. Health Economics and Outcomes Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut, USA.
4. Department of Nephrology, Klinikum Rechts der Isar, Technical University, Munich, Germany.