In the positive predictive value calculation, what does A represent?

In the positive predictive value calculation, what does A represent?

• A. A represents the number of true positives
• B. A represents the number of false positives
• C. A represents the total number of positives
• D. A represents the total number of negatives

Answer: (A)

In the positive predictive value calculation, the numerator is the number of true positives—the people who actually have the disease and test positive. That’s why A represents true positives. PPV is calculated as true positives divided by (true positives plus false positives). The other terms correspond to different parts of the confusion matrix: false positives are those without the disease who test positive; the total positives are true positives plus false positives; the total negatives are true negatives plus false negatives.

In the positive predictive value calculation, the numerator is the number of true positives—the people who actually have the disease and test positive. That’s why A represents true positives. PPV is calculated as true positives divided by (true positives plus false positives). The other terms correspond to different parts of the confusion matrix: false positives are those without the disease who test positive; the total positives are true positives plus false positives; the total negatives are true negatives plus false negatives.