Logistic Baseline: Threshold & ROC Explorer

Fit a logistic baseline on kidney-cohort features and trace how one threshold choice moves you along the ROC curve.

logistic regression
ROC
AUC
threshold

Summary: Out-of-fold (train)

AUC

0.446

90.000

Prevalence

0.122

Sensitivity

0.364

ROC curve

Confusion matrix at current threshold

	Pred +	Pred −
True +	4	7
True −	20	59

Metrics table

Metric	Value
AUC	0.446
Sensitivity	0.364
Specificity	0.747
PPV	0.167
NPV	0.894
Youden's J	0.110

A nearly flat ROC curve cannot be rescued by moving the slider

If the curve barely rises above the diagonal, no threshold recovers both sensitivity and specificity at once — the model's ranking, not the operating point, is the limitation. Compare the out-of-fold curve to the external curve to see how far performance can drift once the model leaves the population it was fit on.

Preparing the simulation…

Conceptual bridges & related modules

EEG Rhythms, Spectra & ERP Averaging
downstream classifier · Chapter 7
Translate synthetic spectral features into discrimination questions without implying a trained EEG classifier.