Table 4.
Performance of the multivariable Cox regression models for CKD
| MODEL 1 | MODEL 2 | MODEL 3 | MODEL 4 | |
|---|---|---|---|---|
| Performance measure | Clinical | Clinical + Classification | MODEL 2 + SCysC | MODEL 2 + pNGAL |
| OVERALL | ||||
|
| ||||
| (a) LR statistic | 70.56 | 123.85 | 69.29 | |
| (b) explained variation (%) | 20.0% | 28.6% | 30.1% | 28.5% |
|
| ||||
| DISCRIMINATION | ||||
|
| ||||
| C statistic | 0.739 | 0.794 | 0.810 | 0.794 |
|
| ||||
| CALIBRATION | ||||
|
| ||||
| slope shrinkage estimate | 0.965 | 0.956 | 0.937 | 0.952 |
|
| ||||
| ADDED VALUE | (c1) | (c2) | (c3) | |
|
| ||||
| NRI events % (CI) | 40.2 (25.8 – 54.7) | 9.2 (−5.7 – 24.1) | 12.4 (−2.3 – 27.1) | |
| NRI non-events % (CI) | 34.5 (24.8 – 44.1) | 41.0 (31.3 – 50.7) | −31.5 (−41.3 – −21.8) | |
|
| ||||
| IDI | 0.10 (0.07 – 0.13) | 0.009 (0.001 – 0.017) | 0.001 (−0.001 – 0.002) | |
| IDI events | 0.07 (0.04 – 0.09) | 0.005 (−0.002 – 0.013) | 0.002 (0.000 – 0.003) | |
| IDI non-events | 0.03 (0.02 – 0.05) | 0.004 (0.000 – 0.007) | −0.001 (−0.002 – 0.000) | |
(a)
For all likelihood-ratio tests: MODEL 1 nested in MODEL 2, and MODEL 2 nested in MODEL 3 and MODEL 4, p<0.001 was obtained;
(b)
Nagelkerke R2;
(c1) corresponds to the added value to the clinical model attained by Classification, on the developed sample; (c2) and (c3) correspond, respectively, to the added value to the clinical + Classification model attained by SCysC and pNGAL, on the developed sample.