Table 1 Formulae for test metrics used to evaluate the performance of diagnostic tests
Test Metric | Formula |
|---|---|
Sensitivity | TP/(TP + FN) |
Specificity | TN/(TN + FP) |
Positive Predictive Value (PPV) | TP/(TP + FP) |
Positive Likelihood Ratio (LR+) | Sensitivity/(1-Specificity) |
Negative Likelihood Ratio (LR-) | (1-Sensitivity)/Specificity |
Accuracy | (TP + TN)/(TP + TN + FP + FN) |
Youden’s Index | Sensitivity + Specificity −1 |
Diagnostic Odds Ratio (DOR) | (TP/FN)/(FP/TN) |