All | 22–27 weeks | 28–32 weeks | |||||||
CRIB | CRIB II | CRIB II(−T) | CRIB | CRIB II | CRIB II(−T) | CRIB | CRIB II | CRIB II(−T) | |
Observed deaths, n (%) | 317 (9.7) | 259 (35.8) | 58 (2.3) | ||||||
Predicted deaths, n (%) | 317.0 (9.7) | 317.0 (9.7) | 317.0 (9.7) | 208.0 (28.7) | 256.1 (35.4) | 259.7 (35.9) | 109.0 (4.3) | 60.9 (2.4) | 57.3 (2.3) |
Brier score | 0.052 | 0.053 | 0.053 | 0.163 | 0.166 | 0.164 | 0.020 | 0.021 | 0.021 |
Spiegelhalter’s z-score | p = 0.2 | p = 0.5 | p = 0.5 | p<0.001 | p = 0.4 | p = 0.6 | p = 1.00 | p = 0.6 | p = 0.4 |
AUC | 0.920 | 0.921 | 0.923 | 0.830 | 0.807 | 0.811 | 0.839 | 0.826 | 0.833 |
Calibration-in-the-small | 0.0002 | 0.0001 | 0.0002 | 0.0085 | 0.0040 | 0.0043 | 0.0013 | <0.0001 | <0.0001 |
Calibration-in-the-large | 0 | 0 | 0 | 0.0050 | <0.0001 | <0.0001 | 0.0004 | <0.0001 | <0.0001 |
Cox’s regression: | |||||||||
Intercept α (SE) | 0 | 0 | 0 | 0.28 (0.11) | 0.02 (0.10) | 0.01 (0.10) | −0.93 (0.22) | −0.24 (0.34) | −0.08 (0.35) |
Slope β (SE) | 1 | 1 | 1 | 0.72 (0.06) | 0.99 (0.08) | 1.03 (0.08) | 0.95 (0.08) | 0.94 (0.10) | 0.97 (0.11) |
Test: α = 0, β = 1 | – | – | – | p<0.001 | p = 0.9 | p = 0.9 | p<0.001 | p = 0.8 | p = 0.9 |
Test: α = 0 | β = 1 | – | – | – | p<0.001 | p = 0.8 | p = 0.9 | p<0.001 | p = 0.7 | p = 0.9 |
Test: β = 1 | α | – | – | – | p<0.001 | p = 0.9 | p = 0.7 | p = 0.5 | p = 0.5 | p = 0.8 |
AUC, area under the curve; CRIB, Clinical Risk Index for Babies; CRIB II(−T), CRIB II without temperature at admission.