SS9

Yes! Here’s the explanation:

As incidence increases PPV increases (assuming sensitivity, specificity are constant) as higher incidence means more true positives, increasing the proportion of people correctly identified. NPV will decrease with higher incidence; there are fewer true negatives and more false negatives, therefore the ratio true neg/true neg+false neg will be a smaller fraction.

PPV and NPV are both important in deciding which test to use on a population/disease. A third term, overall accuracy, combines everything into a single number of, essentially, how much you can trust a result. Calculated by (True positives + True negatives) / (total tests performed).

Which test would have the highest overall accuracy?