A staging system for CKD should classify persons on
the basis of their renal prognosis (25), especially if such
classification influences subsequent management, such as
specialist referral or specific therapies for patients with
more advanced disease. Although the current NKF
KDOQI system for classification of CKD was a notable
achievement, it has been criticized for not meeting these
criteria (26), and others (27–31) have since proposed adding
information about proteinuria to eGFR to better classify
risk among patients with CKD.