Table 2—

Predictive performance of the CG and the MDRD formulae

iGFR [median (interquartile range)]All subjects (n = 292)
Group 1 (iGFR <90; n = 37)
Group 2 (iGFR ≥90; n = 255)
114.9 (22.4)
83.8 (4.3); 84 (81–88)
119.4 (20.3); 115 (103–133)
FormulaCGMDRDCGMDRDCGMDRD
eGFR [median (interquartile range)]101.1 (26.8)89.9 (19.0)78.0 (16.5); 76 (69–88.5)73.7 (12.0); 73 (64–82)104.4 (26.3); 100 (87–120)92.3 (18.7); 89 (78–103)
Bias−13.8 (−16.1 to −11.6)−25.0 (−26.9 to −23.1)−5.8 (−11.1 to −0.6)−10.7 (−14.4 to −7.0)−15.0 (−17.4 to −12.5)−27.1 (−29.1 to −25.1)
Precision19.516.615.711.219.716.2
95% limits of agreement(−52.8 to 25.2)(−58.2 to 8.2)(−37.2 to 25.6)(−33.1 to 11.7)(−54.4 to 24.4)(−59.5 to 5.3)
Accuracy 10%29% (24–35)15% (11–19)32% (19–50)27% (14–44)29% (23–35)13% (9–18)
Accuracy 30%86% (81–89)79% (74–83)86% (17–95)95% (80–99)85% (80–89)76% (71–81)
R20.4900.4760.093*0.1190.4500.429
Gradient0.59 (0.52–0.65)0.81 (0.71–0.91)0.08 (−0.01 to 0.17)0.13 (0.01–0.24)0.52 (0.45–0.59)0.71 (0.61–0.81)
Intercept55.7 (48.5–63.0)41.9 (32.9–51.0)77.6 (70.8–84.4)74.7 (66.1–83.3)65.6 (57.9–73.2)53.8 (44.2–63.3)
  • Data are means ± SD (95% CI), unless otherwise indicated. All R values were positive and, with one exception

  • *

    * , significantly different from zero.