A test with a high positive predictive value indicates what?

• A. A high probability that those who test negative actually have the disease
• B. A high false negative rate
• C. A high false positive rate
• D. A high probability that those who test positive actually have the disease

Answer: (D)

The main idea here is positive predictive value: the probability that a person truly has the disease given a positive test result. When this value is high, most people who test positive actually have the disease, so a positive result is reliable for confirming disease. It’s about how trustworthy a positive result is, not about what happens to those who test negative. That would be negative predictive value. A high false negative rate would indicate problems with sensitivity and affect the likelihood of disease among negatives, while a high false positive rate would undermine the trustworthiness of a positive result, lowering the positive predictive value. So a high PPV means there is a high probability that those who test positive truly have the disease.