Table.

Comparison of the performance of the MDRD and various cystatin C-based formulae for estimating GFR of more than 60 mL/min, adapted from the study by Chudleigh et al. with permission.¹³ In this study of 100 subjects with diabetes, the mean reference isotopic GFR measurement ± SD was 104.5 ± 20 mL/min/1.73m². A full description of the formulae used in the study is contained in the above reference.¹³ Bias is the mean difference between a reference isotopic GFR and GFR estimated by the various formulae. Precision is the standard deviation of the bias. Accuracy refers to the proportion of results that fall within 10% or 30% of reference isotopic GFR measurements.

Reference-isotopic GFR 105 mL/min/1.73m2
Formula	eGFR	Bias	Precision	Accuracy, %
				10%	30%
MDRD	77.4	−27.1	18.0	10	65
Perkins	124.5	20.0	29.5	21	64
Arnal	101.7	−2.8	32.2	30	75
Rule	90.0	−14.5	28.4	31	68
MacIsaac	102.1	−2.4	26.0	34	85
Tan	101.6	−2.9	26.6	34	84
Stevens *	96.0	−8.5	28.1	29	75
Stevens †	85.6	−18.9	19.0	27	78

^*Formula incorporates cystatin C, age and gender.

^†Formula incorporates cystatin C, age and gender plus creatinine levels.