Which of the following measures will always include true positives and true negatives in its calculation?

The correct choice is accuracy because it is defined as the ratio of the total number of correct predictions (true positives and true negatives) to the total number of cases examined. Accuracy takes into account both how many positive cases were correctly identified (true positives) and how many negative cases were correctly identified (true negatives). It provides a comprehensive measure of a test's performance by incorporating all true results and comparing them to the total number of results, thus giving a full picture of the test’s reliability in a clinical setting.

In contrast, sensitivity focuses specifically on true positives and does not consider true negatives, while specificity concentrates on true negatives without including true positives. Positive predictive value measures the proportion of true positives among all positive results, but it also doesn't account for true negatives. Thus, accuracy is the only measure among the options that consistently includes both true positives and true negatives in its calculation.