Performance of the Cockcroft-Gault and MDRD equations in adult Nigerians with chronic kidney disease

Abstract

Background: Estimation of the glomerular filtration rate (GFR) is required in the assessment of patients with chronic kidney disease (CKD) in order to provide information regarding the functional status of the kidneys. Current guidelines advocate the use of prediction equations, such as the Cockcroft-Gault (CG) formula and the Modification of Diet in Renal Disease (MDRD) study-derived equations, over clearance of endogenous creatinine (Ccr) in achieving this aim. We were interested in knowing the accuracy of these equations in predicting the GFR in adult Nigerians with CKD.

Methods: We conducted a review of records of patients who were evaluated for CKD at the Nephrology Clinic of the Jos University Teaching Hospital between 2001 and 2003. We compared the CG and MDRD equations against the Ccr in predicting the GFR in 130 patients (88 males and 42 females) with CKD.

Results: The means +/- standard deviation (SD) for the measured and predicted GFR by the CG and MDRD equations were similar (17.6 +/- 25.8 ml/min, 19.9 +/- 24.0 ml/min and 21.5 +/- 28.2 ml/min, respectively; analysis of variance [ANOVA], F = 0.68, P = 0.5). The mean difference between CG and Ccr was -2.2 +/- 14.8 ml/min, with discordance at Ccr values >25 ml/min. The mean difference between MDRD and Ccr was -3.9 +/- 18.1 ml/min, with discordance at Ccr values >40 ml/min.

Conclusion: The CG and MDRD equations provide reliable alternatives to measured Ccr in the estimation of the GFR in Nigerian patients with CKD.