MDRD or CKD-EPI study equations for estimating prevalence of stage 3 CKD in epidemiological studies: which difference? Is this difference relevant?
BACKGROUND
Prevalence of stage 3 chronic kidney disease (CKD) is increasing according to the NHANES study. Prevalence has been calculated using the MDRD study equation for estimating glomerular filtration rate (GFR). Recently, a new estimator based on creatinine, the CKD-EPI equation, has been proposed which is presumed to better perform in normal GFR ranges. The aim of the study was to measure the difference in prevalence of stage 3 CKD in a population using either the MDRD or the CKD-EPI study equations.


METHODS
CKD screening is organized in the Province of Liège, Belgium. On a voluntary basis, people aged between 45 and 75 years are invited to be screened. GFR is estimated by the MDRD study equation and by the "new" CKD-EPI equations.


RESULTS
The population screened consisted in 1992 people (47% of men). Mean serum creatinine was 0.86 +/- 0.20 mg/dL. The prevalence of stage 3 CKD in this population using the MDRD or the CKD-EPI equations was 11.04 and 7.98%, respectively. The prevalence of stage 3 CKD is significantly higher with the MDRD study equation (p < 0,0012).


CONCLUSIONS
Prevalence of stage 3 CKD varies strongly following the method used for estimating GFR, MDRD or CKD-EPI study equations. Such discrepancies are of importance and must be confirmed and explained by additional studies using GFR measured with a reference method.
Delanaye
Pierre
P
Department of Nephrology-Dialysis-Transplantation, University of Liège, CHU Sart Tilman, Liège, Belgium. pierre_delanaye@yahoo.fr
Cavalier
Etienne
E
Mariat
Christophe
C
Maillard
Nicolas
N
Krzesinski
Jean-Marie
JM
D000367:Age Factors; D000368:Aged; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000453:epidemiology* / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015995:Prevalence
D003404:Creatinine