1. Division of Nephrology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York
2. Columbia University Renal Epidemiology Group, New York, New York
3. Department of Surgery and Perioperative Care, Dell Medical School, University of Texas at Austin, Austin
4. Department of Surgery, University of Colorado, Anschutz Medical Campus, Aurora
5. Department of Epidemiology, School of Public Health, University of Colorado, Anschutz Medical Campus, Aurora
6. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York