[1] SUNY Buffalo, Dept Med, Buffalo, NY 14215 USA
[2] SUNY Buffalo, Dept Social & Prevent Med, Buffalo, NY 14215 USA
[3] Univ Calif Los Angeles, Vet Adm Med Ctr, Los Angeles, CA USA
[4] Charite, Dept Nephrol, Berlin, Germany
[5] Arbeitsgemeinsch Koordinierungsausschuss, Siegburg, Germany
[6] McMaster Univ, Dept Clin Epidemiiol & Biostat, Hamilton, ON L8N 3Z5, Canada