What is specificity?

What is specificity?

• A. Proportion of true positives
• B. Proportion of true negatives
• C. Proportion of false negatives
• D. Proportion of false positives

Answer: (B)

Specificity is the proportion of true negatives among those who do not have the condition. In other words, it measures how accurately a test identifies healthy individuals. Specificity = true negatives / (true negatives + false positives). A high specificity means few false positives, so the test is good at ruling out disease in people without it. That’s why the option describing true negatives is the correct match. For comparison, sensitivity is the proportion of true positives among those who have the condition (how well the test detects disease), while the other measures refer to false negatives or false positives.

Specificity is the proportion of true negatives among those who do not have the condition. In other words, it measures how accurately a test identifies healthy individuals. Specificity = true negatives / (true negatives + false positives). A high specificity means few false positives, so the test is good at ruling out disease in people without it. That’s why the option describing true negatives is the correct match. For comparison, sensitivity is the proportion of true positives among those who have the condition (how well the test detects disease), while the other measures refer to false negatives or false positives.