Difference against mean of rate of decline in measured GFR (51Cr-EDTA) and estimated GFR (A: Cockcroft-Gault [CG] formula, B: MDRD formula) in 156 microalbuminuric (•) and 227 macroalbuminuric (○) type 2 diabetic patients. The average difference between the methods (the bias) in microalbuminuric patients for the Cockcroft-Gault formula was an underestimation of decline of 0.7 (95% limits of agreement −8.15 to 6.85) and for the MDRD equation was an underestimation of 1.1 (−8.46 to 6.26) ml · min−1 per 1.73 m2 per year compared with measured GFR. In patients with nephropathy, these was values were underestimations of 0.6 (−6.3 to 4.3) for the Cockcroft-Gault formula and 1.0 (−6.0 to 4.9) ml · min−1 per 1.73 m2 per year for the MDRD equation.