Rate of Kidney Function Decline Associates with Increased Risk of Death

The current classification scheme for chronic kidney disease (CKD) does not differentiate between patients who show a progressive course of CKD and those whose kidney function remains stable over a long period. There is an association of faster progression of CKD with worse mortality, suggesting that an individual's slope of estimated GFR (eGFR) over time could help us refine the prognosis for patients with any given stage of CKD. Many questions still need to be answered before the mainstream application of the slopes of eGFR is possible.The estimation formula-based CKD classification by the Kidney Disease Outcomes Quality Initiative (K/DOQI)1 has proved to be an eye opener to the medical community and has raised awareness about the common frequency of decreased eGFR and the high mortality associated with lower eGFR.2–5 The immediate impact of this awareness has been a significant increase of clinical referrals to nephrologists from various practitioners6 who suddenly discovered that many of their patients had CKD,7 a condition that became easy to diagnose but whose management still befuddles many nonspecialists. Those of us on the receiving end of these consultations have quickly come to realize that some patients who are labeled as having CKD received a misdiagnosis because of deficiencies in our estimation formulas or of standardization of serum creatinine measurements,8 and many patients, of course, who indeed have …