. Author manuscript; available in PMC: 2012 Feb 1.

Published in final edited form as: Kidney Int. 2011 Jun 8;80(4):423–430. doi: 10.1038/ki.2011.155

Table 4.

Tables 4a and 4b. Agreement of the estimated GFR ( ${\hat{GFR}}_{2, 2}$ ) based on two-point GFR from the slow curve only (GFR_0,2) and selected models with the observed four-point GFR (GFR_2,2) in the MACS (n= 177) and CKiD (n= 274) validation datasets.

Table 4a
	MACS Validation Dataset (n= 177)

Model of ${\hat{GFR}}_{2, 2}$ as a function of GFR_0,2 and BSA	Source	Bias Ratio (95% CI)	Ratio of SDs^a (95% CI)	Correlation (95% CI)	RMSE^b	% of ${\hat{GFR}}_{2, 2}$ within 5% of GFR_2,2
Original Brochner-Mortensen C₁ (GFR_0,2/100) + C₂ (GFR_0,2/100)² C₁ = 98.31; C₂ = −0.1218	Brochner- Mortensen (1972)[4]	0.967 (0.961, 0.973)	0.937 (0.909, 0.965)	0.978 (0.971, 0.984)	6.49	62.7%
GFR_0,2 / [1+ B₀ × (GFR_0,2/100) ^B1 × BSA^B2] B₀ = 0.185; B₁ = 1, B₂ = −0.3	Brochner- Mortensen & Jodal (2009) [8,9]	0.972 (0.967, 0.978)	0.960 (0.934, 0.986)	0.979 (0.972, 0.984)	5.80	66.1%
GFR_0,2 / [1+B₀ × (GFR_0,2/100) ^B1] B₀ = 0.17; B₁ = 1	Fleming (2007) [7]	0.953 (0.947, 0.959)	0.941 (0.916, 0.967)	0.979 (0.972, 0.984)	7.49	49.7%
MACS & CKiD Proposed Equation GFR_0,2 / [1+B₀ × (GFR_0,2/100)^B1] B₀ = 0.12; B₁ = 1	Training Set CKiD + MACS 2/3 random sample (n=896)	1.005 (1.000, 1.011)	0.987 (0.962, 1.013)	0.980 (0.972, 0.985)	4.59	79.1%

Table 4b
	CKiD Validation Dataset (n= 274)

Model of ${\hat{GFR}}_{2, 2}$ as a function of GFR_0,2 and BSA	Source	Bias Ratio (95% CI)	Ratio of SDs^a (95% CI)	Correlation (95% CI)	RMSE^b	% of ${\hat{GFR}}_{2, 2}$ within 5% of GFR_2,2
Original Brochner-Mortensen C₁ (GFR_0,2/100) + C₂ (GFR_0,2/100)² C₁ = 101.0; C₂ = −0.17	Brochner- Mortensen (1974)[6]	0.983 (0.980, 0.986)	0.968 (0.959, 0.976)	0.996 (0.995, 0.997)	2.04	91.2%
GFR_0,2 / [1+ B₀ × (GFR_0,2/100)^B1 × BSA^B2] B₀ = 0.185; B₁ = 1, B₂ = −0.3	Brochner- Mortensen & Jodal (2009) [8,9]	0.978 (0.975, 0.981)	0.984 (0.976, 0.992)	0.996 (0.995, 0.997)	1.92	86.5%
GFR_0,2 / [1+B₀ × (GFR_0,2/100)^B1] B₀ = 0.17; B₁ = 1	Fleming (2007) [7]	0.980 (0.978, 0.983)	0.983 (0.974, 0.991)	0.996 (0.995, 0.997)	1.87	90.9%
MACS & CKiD Proposed Equation GFR_0,2 / [1+B₀ × (GFR_0,2/100) ^B1] B₀ = 0.12; B₁ = 1	Training Set CKiD + MACS 2/3 random sample (n=896)	1.004 (1.001, 1.006)	1.005 (0.996, 1.013)	0.996 (0.995, 0.997)	1.46	96.0%

Bold indicates statistically significantly different from 1 (i.e., p < 0.05);

SDs, standard deviations

RMSE, root mean square error