Which statement describes PPV and NPV definitions?

• A. A positive predictive value is the probability that a person with a positive test truly has the disease; a negative predictive value is the probability that a person with a negative test truly does not have the disease.
• B. A positive predictive value is the probability that a person with a negative test truly does not have the disease; a negative predictive value is the probability that a person with a positive test truly has the disease.
• C. PPV and NPV are independent of disease prevalence.
• D. PPV and NPV are both determined solely by test sensitivity and specificity.

Answer: (A)