Definition and classification of CKD: the debate should be about patient prognosis--a position statement from KDOQI and KDIGO.

摘要

In 2002 the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) published a guideline on chronic kidney disease (CKD) covering evaluation, classification, and stratification of risk. The workgroup developing this guideline provided a new conceptual framework for a diagnosis of CKD independent of cause, and developed a classification scheme of kidney disease severity based on the level of glomerular filtration rate (GFR). Before this new system for defining and staging CKD was developed, vague and variable terminology, such as "chronic renal failure," "chronic renal insufficiency," "pre-dialysis," and "pre-end-stage renal disease" prevented the use of a common and precise language.2 The new system also represented a significant conceptual change, since kidney disease historically had been categorized mainly by cause. The definition is based on 3 components: (1) an anatomical or structural component (markers of kidney damage, including albuminuria), (2) a functional component (based on GFR), and (3) a temporal component (at least 3 months' duration of structural and/or functional alterations). The diagnosis of CKD relies on markers of kidney damage and/or a reduction in GFR. Stages 1 and 2 define conditions of kidney damage in the presence of a GFR of at least 90 mL/min/1.73 m~2 or 60 to 89 mL/min/ 1.73 m~2, respectively, and stages 3 to 5 define conditions of moderately and severely reduced GFR irrespective of markers of kidney damage (Table 1).