What sensitivity and specificity measure
Sensitivity and specificity describe how well a test distinguishes between positive and negative cases. Sensitivity is the proportion of actual positives correctly identified, while specificity is the proportion of actual negatives correctly identified.
The formulas
Sensitivity = True Positives / (True Positives + False Negatives). Specificity = True Negatives / (True Negatives + False Positives). Positive Predictive Value (PPV) = True Positives / (True Positives + False Positives). Negative Predictive Value (NPV) = True Negatives / (True Negatives + False Negatives). Accuracy = (True Positives + True Negatives) / Total Cases.
This calculator is for general educational and statistical planning purposes only and is not a substitute for professional or clinical interpretation of test performance.