Table 6.
Performance of the multivariable Cox regression models for death
| MODEL 1 | MODEL 2 | MODEL 3 | MODEL 4 | |
|---|---|---|---|---|
| Performance measure | Clinical | Clinical + Classification | MODEL 2 + SCysC | MODEL 2 + pNGAL |
| OVERALL | ||||
|
| ||||
| (a) LR statistic | 20.24 | 41.00 | 24.53 | |
| (b)% of explained variation | 17.0% | 18.98% | 19.87% | 19.72% |
|
| ||||
| DISCRIMINATION | ||||
|
| ||||
| C statistic | 0.738 | 0.755 | 0.758 | 0.753 |
|
| ||||
| CALIBRATION | ||||
|
| ||||
| slope shrinkage estimate | 0.956 | 0.925 | 0.906 | 0.915 |
|
| ||||
| ADDED VALUE | (c1) | (c2) | (c3) | |
|
| ||||
| NRI events % (CI) | −13.2 (−28.8 – 2.3) | 12.1 (−3.5 – 27.7) | 26.6 (11.0 – 42.2) | |
| NRI non-events % (CI) | 50.3 (41.1 – 59.5) | 8.4 (−0.1 – 17.8) | 4.8 (−4.6 – 14.1) | |
|
| ||||
| IDI | 0.034 (0.017 – 0.050) | 0.014 (0.002 – 0.027) | 0.009 (0.003 – 0.014) | |
| IDI events | 0.026 (0.011 – 0.041) | 0.017 (0.006 – 0.029) | 0.012 (0.007 – 0.017) | |
| IDI non-events | 0.008 (0.000 – 0.015) | −0.003 (−0.008 – 0.002) | −0.004 (−0.006 – −0.001) | |
(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.