[1] Univ Calif San Francisco, Vet Affairs Med Ctr, Gen Internal Med Sect, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA 94143 USA
[4] Collaborat Hlth Studies Coordinating Ctr, Seattle, WA USA
[5] Vet Affairs Pittsburgh Healthcare Syst, Renal Sect, Med Serv, Pittsburgh, PA USA
[6] Univ Vermont, Coll Med, Dept Pathol, Burlington, VT 05405 USA
[7] Amgen Inc, Thousand Oaks, CA 91320 USA
[8] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Epidemiol, Pittsburgh, PA USA
[9] Univ Pittsburgh, Sch Med, Div Geriatr Med, Pittsburgh, PA USA
[10] Univ Washington, Dept Med, Seattle, WA 98195 USA
[11] Univ Washington, Dept Epidemiol, Seattle, WA 98195 USA
[12] Univ Washington, Dept Hlth Serv, Seattle, WA 98195 USA
[13] Tufts Univ, New England Med Ctr, Dept Med, Div Nephrol, Boston, MA 02111 USA