1. Department of Medicine (Nephrology), Stanford University, Palo Alto, California (S.A., M.E.M., J.H., P.G.)
2. Ascend Clinical Laboratory, Redwood City, California (L.C., P.H., C.M., R.K., P.B.)
3. U.S. Renal Care, Plano, Texas (M.D.)
4. U.S. Renal Care, Golden, Colorado (G.A.B.)
5. Departments of Medicine (Nephrology) and Epidemiology and Population Health, Stanford University, Stanford, California (G.M.C.)
6. Departments of Medicine (Infectious Diseases and Geographic Medicine) and Epidemiology and Population Health, Stanford University, Stanford, California (J.P.)