6Levey AS,Eckardt KU,Tsukamoto Y,et al.Definition and classification of chronic kidney disease:a position statement from Kidney Disease:Improving Global Outcomes (KDIGO).Kidney Int,2005,67:2089-2100.
7Stevens LA,Levey AS.Chronic kidney disease in the elderly-how to assess risk.N Engl J Med,2005,352:2122-2124.
8Coresh J,Astor BC,Greene T,et al.Prevalence of chronic kidney disease and decreased kidney function in the adult US population:Third National Health and Nutrition Examination Survey.Am J Kidney Dis,2003,41:1-12.