“The KDOQI group did not adjust the thresholdsdifferentiating normal from abnormal based on age and gender, and that, in myview, was a serious mistake because eGFR declines in all people as theyage—everyone,” Dr. Glassock asserts.
“If the KDOQI guidelines applied only towhite males under the age of 45, the KDOQI criteria are just fine, but 80% ofpeople diagnosed as having CKD using these criteria are over 65. The normal GFRin a 75-year-old woman is close to 40 [mL/min] rather than 60, but KDOQI callsless than 60 chronic kidney disease, so the problem is that elderly women inparticular are being overdiagnosed as having CKD by the KDOQI criteria. For a75-year-old man, normal is about 45 or 50.”
Dr. Glassock says the data so far seem to indicate that thenumber of patients who were “appropriately referred—that is, who have truekidney disease—is far, far less than [the number] who were referredinappropriately and who do not have kidney disease.”
He calls the 2002 adoption of the guidelines premature. “TheKDOQI working group should have waited until better data were available toidentify what the proper criteria were, or [they should have] come back andrevised them after they found the criteria were incorrect,” Dr. Glassock says. “Thathasn’t happened.”
Drs. Glassock and Winearls took their concerns to the“Controversies in Nephrology” section of the Clinical Journal of the American Society of Nephrology (2008;3:1563-1568).They objected to the screening of unselected populations not known to be atrisk of CKD by means of the eGFR formula, KDOQI staging system, and other tools“of dubious value,” warning of the inherent dangers of such screening.
This was published alongside counterargumentspresented by the Thomas Hostetter, MD, director of the Nephrology Division atAlbert Einstein College of Medicine, Bronx,N.Y., and fellow Einsteinnephrologists Michal L. Melamed, MD, and Carolyn Bauer, MD. Thegroup noted that mass or universal screening was not the purpose of eGFRreporting, agreed it did not seem justified, and even agreed that the KDOQIstaging system leads to “disturbingly high estimates” of CKD.
But Dr. Hostetter and his co-authors advocated eGFR as just one tool that can be used to help reducethe “even more disturbing fraction of people with serious and progressive renaldisease [who] are not diagnosed, counseled, or treated.”
“I think laboratories ought to report if creatinine leads toan estimated GFR less than 60; I think that’s perfectly justifiable,” remarksDr. Hostetter, a one-time director of the NIH’s National Kidney DiseaseEducation Program (NKDEP). “All it does is provide a more meaningful reflectionof kidney function for clinicians who are not kidney doctors. I’m not a bigproponent of staging, of saying you have stage 3 or stage 4 or stage 5. Thelaboratories just ought to report the estimated GFR, whatever it is.”