Test measures
| Reference standard | Outcome | Test measures | ||
| Positive | Negative | |||
| Diagnostic algorithm | ||||
| Positive | True positives correctly identified (A) | False positives (B) | Total identified as positive | PPV=A/(A+B) |
| Negative | False negatives (C) | True negatives correctly identified (D) | Total identified as negative | NPV=D/(C+D) |
| Outcome | True positives | True negatives | ||
| Test measures | Sensitivity=A/(A+C) | Specificity=D/(B+D) | ||