Time to differentiate 'decreased kidney function' from 'kidney disease': towards improving the definition of chronic kidney disease.

Chronic kidney disease (CKD) has become an 'epidemic' worldwide, since the publication of K/DOQI guidelines in 2002. This classification indeed has raised the profile of CKD worldwide. However, despite limitations of the glomerular filtration rate (GFR) estimating equations, the majority of this epidemic is caused by the large number of persons with stage 3 CKD, with many elderly individuals with 'low-normal GFR' being diagnosed with CKD, when, in fact, the majority of those may not have the disease, and a handful of resources being utilized in investigating these relatively 'low-risk patients' with 'decreased eGFR' without CKD. Recently, concerns have been raised by nephrologists about this classification system, and I strongly feel that it is important to differentiate 'decreased kidney function' from 'kidney disease', as the GFR estimating equations predict renal function only and nothing else; therefore, I propose some modifications to improve the current classification, so that limited resources and efforts are effectively focused on managing high-risk patients.