Table 3 Performance within internal and internal-external validation, including recalibrated intercept and slope of the three models.

From: Postpartum depression: a developed and validated model predicting individual risk in new mothers

 

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

  1. 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.
  2. 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).
Back to article page