Renal risk scores: progress and prospects

Worldwide adoption of the Kidney Disease Outcomes Quality Initiative classification for chronic kidney disease (CKD) and widespread use of the estimated glomerular filtration rate to assess renal function have identified large numbers of patients with previously undiagnosed CKD. It is clear, however, that this is a heterogeneous group and that only a small minority of such patients ever progress to end-stage renal disease. There is thus an urgent need for a simple method of risk assessment that can be applied to all patients with CKD to identify those few at greatest risk. The magnitude of baseline proteinuria has long been recognized as an important predictor of renal prognosis. Furthermore, several studies have found that change in proteinuria after initiation of antihypertensive treatment as well as achieved level of proteinuria correlate with prognosis. Thus, proteinuria has emerged as the single most important marker of renal risk. Many other factors have been identified as risk factors for CKD progression. Several attempts have been made to combine a relatively small number of risk factors into a risk score to predict renal outcomes in specific groups of patients. Validation of these risk scores as well as further studies are now required to develop a renal risk score applicable to a more general population of patients with CKD. Similar methodology could be applied to assess the important issue of the cardiovascular risk associated with CKD.