| Reference standard (disease status) | Test accuracy measures ↓ | ||
---|---|---|---|---|
Disease present | Disease absent | |||
Index test (test under evaluation) | Positive result | True positive (TP) | False positive (FP) | Positive predictive value = TP/(TP+FP) |
Negative result | False negative (FN) | True negative (TN) | Negative predictive value= TN/(TN+FN) | |
Test accuracy measures → | Sensitivity = TP/(TP+FN) | Specificity = TN/(TN+FP) | Diagnostic odds ratio = (TPxTN)/(FPxFN) |