Table 3.
Performance within internal and internal-external validation, including recalibrated intercept and slope of the three models.
| AUC (95%CI) | Calibration intercept | Calibration slope | CHCH test, p | |
|---|---|---|---|---|
| Internal, 1997–2012 | ||||
| Core | 0.795 (0.790-0.802) | 0.001a | 1.000a | 0.082 |
| Ext | 0.801 (0.796-0.807) | −0.007a | 0.998a | 0.060 |
| Ext+ | 0.809 (0.804-0.815) | −0.005a | 0.999a | 0.003 |
| Internal-external, 2013–2015 | ||||
| Core | 0.804 (0.796-0.812) | 0.140 | 1.079 | 0.165b |
| Ext | 0.808 (0.800-0.816) | 0.107 | 1.068 | 0.144b |
| Ext+ | 0.812 (0.804-0.820) | 0.091 | 1.074 | 0.126b |
aThe optimism-corrected calibration intercept and –slope, estimated using 200 bootstrapped samples. The slope is equivalent to the uniform shrinkage factor mentioned in the section Internal validation.
bThe CHCH goodness of fit test is specified for the recalibrated models. The tests were rejected when considering the fit of the three developed models within the validation sample (p < 0.001, results not shown).