Implications of the CKD-EPI GFR estimation equation in clinical practice.
OBJECTIVE
Chronic kidney disease (CKD) is a significant public health problem whose diagnosis and staging relies upon GFR-estimating equations, including the new CKD-EPI equation. CKD-EPI demonstrated superior performance compared with the existing MDRD equation but has not been applied to a healthcare system.


METHODS
We identified 53,759 patients with stages 3 to 5 CKD on the basis of either MDRD or CKD-EPI equations using two eGFR values <60 ml/min per 1.73 m² > 90 days apart from an outpatient setting. We compared patient characteristics, presence of related diagnosis codes, and time CKD classification between equations.


RESULTS
The number of patients identified with CKD decreased 10% applying CKD-EPI versus MDRD. Changes varied substantially by patient characteristics including a 35% decrease among patients < 60 years and a 10% increase among patients > 90 years. Women, non-African Americans, nondiabetics, and obese patients were less likely to be classified on the basis of CKD-EPI. Time to CKD classification was significantly longer with CKD-EPI among younger patients. 14% of patients identified with CKD on the basis of either estimating equation also had a related ICD-9 diagnosis, ranging from 19% among patients < 60 years to 7% among patients > 90 years.


CONCLUSIONS
Consistent with findings in the general population, CKD-EPI resulted in substantial declines in equation-based CKD diagnoses in a large healthcare system. Further research is needed to determine whether widespread use of CKD-EPI with current guidelines could lead to delayed needed care among younger patients or excessive referrals among older patients.
Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio, USA.
Jesse D
JD
Schold
Sankar D
SD
Navaneethan
Stacey E
SE
Jolly
Emilio D
ED
Poggio
Susana
S
Arrigain
Welf
W
Saupe
Anil
A
Jain
John W
JW
Sharp
James F
JF
Simon
Martin J
MJ
Schreiber
Joseph V
JV
Nally
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D002908:Chronic Disease; D003695:Delivery of Health Care; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009820:Ohio; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D055815:Young Adult