In 2002, the NKF-K/DOQI, using an evidence-based approach through its Kidney Disease Outcomes Quality Initiative (K/DOQI), developed and published for the first time a system for the definition and classification of stages of chronic kidney disease (CKD). The four core elements of this system are:

• A definition of CKD based on reduction of GFR in combination with signs of kidney damage

• A staging system of the severity of CKD based on the degree of reduction of GFR

• The proposal that both the definition and staging should be based on an estimate of GFR derived from the measurement of serum creatinine by the use of appropriate prediction equations

• The proposal that proteinuria be quantitated using the ratio of albumin / protein to creatinine concentrations in spot urine samples

The goals of this conference were to 1) provide a clear understanding to both the nephrology and non-nephrology communities of the evidence base fir the definition and classification recommended by KDOQI, (2) develop global consensus for the adoption of a simple definition and classification system, and (3) identify a collaborative research agenda and plan that would improve the evidence base and facilitate implementation of the definition and classification of CKD.