Variability of glomerular filtration rate estimation equations in elderly Chinese patients with chronic kidney disease

Figures & data

Table 1 Patient characteristics

CKD cause
Diabetic nephropathy	114 (35.7)
Hypertension	74 (23.2)
Chronic tubulointerstitial disease	53 (16.6)
Primary glomerular disease	36 (11.3)
Renovascular disease	22 (6.9)
Other causes or causes unknown	20 (6.3)
Age (year)	70.0 ± 6.8 (60–93)
Male/female (%)	62.1/37.9
Weight (kg)	61.4 ± 11.5 (30–98)
Height (cm)	162.0 ± 8.1 (142–184)
BSA (m^2)	1.65 ± 0.17 (1.15–2.18)
SC (umol/L)	245.0 ± 210.2 (32–1833)
DTPA-GFR (mL/min/1.73 m^2)	39.4 ± 21.8 (5.7–116.6)

Note: Results are expressed as mean ± SD (range) or n (%).

Abbreviations: BSA, body surface area; SC, serum creatinine; DTPA-GFR, technetium- 99m diethylenetriaminepentaacetic acid-glomerular filtration rate.

Table 2 Overall performances of eGFR and sGFR

	Precision	Difference			Accuracy within			CKD stage misclassification
		Mean	Median	IQR	15%	30%	50%
Cockcroft–Gault equation	58.5	−3.0	−4.3	13.9	31.3	57.7	81.5	43.9
Six-variable MDRD equation	69.2	1.0	−1.2	16.0	29.5	53.6	76.5	44.2
Four-variable MDRD equation	73.4	2.4	−0.3	17.6	27.9	54.5	74.9	42.9
CKD-EPI equation	62.4	−0.6	−1.9	16.7	27.6	54.9	75.5	44.2
Jelliffe-1973 equation	76.4	0.8	−1.8	15.1	30.1	57.1	81.2	43.6
Hull equation	64.2	−1.9	−3.9	14.6	32.9	55.2	79.3	43.9

Abbreviation: IQR, interquartile range.

Table 3 AUCs, sensitivity, and specificity of eGFR for the diagnosis of moderate renal failure (GFR < 60 mL/min/1.73 m²)

	AUC	Sensitivity	Specificity
Cockcroft–Gault equation	0.903 ± 0.019	0.593	0.917
Six-variable MDRD equation	0.909 ± 0.018	0.815	0.868
Four-variable MDRD equation	0.906 ± 0.019	0.796	0.872
CKD-EPI equation	0.908 ± 0.019	0.778	0.883
Jelliffe-1973 equation	0.919 ± 0.017	0.630	0.925
Hull equation	0.904 ± 0.019	0.667	0.917

Note: P < 0.05 comparing with Jelliffe-1973-GFR.

Abbreviations: AUC, area under the receiver operating characteristic curve; eGFR, estmated glomerular filtration rate.

Figure 1 Bland–Altman plot of eGFR and sGFR (mL/min/1.73 m²). Solid line represents the mean of difference between methods; dashed lines represent 95% limits of agreement of the mean of difference between methods. (A–F) Represent for the GFR results estimated using Cockcroft–Gault equation, six-variable MDRD equation, four-variable MDRD equation, CKD-EPI equation, Jelliffe-1973 equation, and Hull equation, respectively.

Abbreviations: CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; eGFR, estimated glomerular filtration rate; sGFR, standard glomerular filtration rate; MDRD, Modification of Diet in Renal Disease.

Figure 2 Receiver operating characteristic curves of eGFR for the diagnosis of moderate renal failure (GFR < 60 mL/min/1.73 m²).

Notes: Cockcroft–Gault, MDRD6, MDRD4, CKDEPI, Jelliffe-1973, and Hull represent the results of GFR estimated by Cockcroft–Gault equation, six-variable MDRD equation, four-variable MDRD equation, CKD-EPI equation, Jelliffe-1973 equation, and Hull equation, respectively.
Abbreviations: CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; eGFR, estimated glomerular filtration rate; sGFR, standard glomerular filtration rate; MDRD, Modification of Diet in Renal Disease.

Table 4 Performances of eGFR and sGFR in the different stages of CKD

	Difference		Accuracy within
	Median	IQR	15%	30%	50%
Stage 1–2
Cockcroft–Gault equation	−10.8	29.1	35.2	70.4	92.6
Six-variable MDRD equation	5.9	29.5	42.6	66.7	87.0
Four-variable MDRD equation	6.6	33.0	38.9	61.1	83.3
CKD-EPI equation	2.2	23.9	50.0	74.1	94.4
Jelliffe-1973 equation	0.0	44.3	24.1	64.8	79.6
Hull equation	−6.2	30.4	33.3	68.5	90.7
Stage 3
Cockcroft–Gault equation	−3.8	16.9	37.8	62.9	83.9
Six-variable MDRD equation	−0.4	22.7	30.1	56.6	78.3
Four-variable MDRD equation	3.8	22.3	29.4	60.1	76.9
CKD-EPI equation	1.3	21.1	28.7	58.7	76.2
Jelliffe-1973 equation	−2.2	20.2	34.3	58.7	86.7
Hull equation	−3.3	18.2	38.5	61.5	81.8
Stage 4–5
Cockcroft–Gault equation	−2.8	9.7	22.1	45.9	73.8
Six-variable MDRD equation	−2.4	11.0	23.0	44.3	69.7
Four-variable MDRD equation	−2.6	10.9	21.3	45.1	68.9
CKD-EPI equation	−4.2	11.2	16.4	41.8	66.4
Jelliffe-1973 equation	−1.8	9.7	27.9	51.6	75.4
Hull equation	−4.1	10.2	26.2	41.8	71.3

Abbreviations: IQR, interquartile range; eGFR, estimated glomerular filtration rate; sGFR, standard glomerular filtration rate.