Comparison of creatinine clearance estimates with routine measured clearance

Objectives: Compare GFR estimates (eGFR) calculated by formulas (CG, CGI, MDRD) and creatinine clearance (CrCl), in subgroups based on sex, age, BMI and serum creatinine (Cr). Design and methods: eGFR is calculated with Cockgroft–Gault (CG), CG corrected for ideal or lean weight (CGI), and Modification of Diet in Renal Disease (MDRD) formulas using a compensated kinetic Jaffé method. Comparison of means and correlations relative to CrCl is done with 666 male and female adult subjects in different subgroups. Results: Comparatively to CrCl, most subgroups are best correlated with MDRD, especially with high Cr. However, in men < 65 years, a factor of 222, instead of 186 in MDRD formula, is better. Conclusions: eGFR from MDRD formula, modified for men < 65 years, is better correlated to CrCl.