Table 3 Performance metrics used for model evaluation across folds and repetitions.
Metric | Definition | Interpretation |
|---|---|---|
Accuracy | \(\dfrac{\text {TP + TN}}{\text {TP + TN + FP + FN}}\) | Overall proportion of correct classifications. |
Positive predictive value (PPV, also called precision) | \(\dfrac{\text {TP}}{\text {TP + FP}}\) | Probability that a predicted positive is truly positive. |
Negative predictive value (NPV) | \(\dfrac{\text {TN}}{\text {TN + FN}}\) | Probability that a predicted negative is truly negative. |
Sensitivity (also called recall) | \(\dfrac{\text {TP}}{\text {TP + FN}}\) | Proportion of true hospitalized patients correctly classified. |
Specificity | \(\dfrac{\text {TN}}{\text {TN + FP}}\) | Accuracy in identifying non-hospitalized individuals. |
F1-score | \(2 \times \left( \dfrac{\text {PPV} \times \text {sensitivity}}{\text {PPV} + \text {sensitivity}}\right)\) | Balances overfitting positives and missing true positives. |