1. Department of Internal Medicine, Division of Nephrology, Bone and Mineral Metabolism, University of Kentucky Medical Center, Lexington, KY, USA
2. Department of Statistics, University of Kentucky, Lexington, Kentucky, USA
3. School of Medicine, Universidad Mayor San Simon, Cochabamba, Bolivia
4. Department of Internal Medicine, Division of Nephrology, Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
5. Center for Acute Care Nephrology, Cincinnati Children’s Hospital and Medical Center, University of Cincinnati, Cincinnati, OH, USA