What is sensitivity in diagnostic testing?

What is sensitivity in diagnostic testing?

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

Answer: (A)

Sensitivity is the proportion of people with the condition who are correctly identified as positive by the test. In other words, it’s the true positive rate: among those who actually have the disorder, what fraction tests positive? For example, if 100 people truly have the condition and 90 test positive, the sensitivity is 90%. A high sensitivity means the test is good at catching cases and yields few false negatives (those with the condition who test negative). This is why the correct description is the proportion of true positives. (In contrast, specificity, not asked here, is the proportion of true negatives among those without the condition.)

Sensitivity is the proportion of people with the condition who are correctly identified as positive by the test. In other words, it’s the true positive rate: among those who actually have the disorder, what fraction tests positive? For example, if 100 people truly have the condition and 90 test positive, the sensitivity is 90%. A high sensitivity means the test is good at catching cases and yields few false negatives (those with the condition who test negative). This is why the correct description is the proportion of true positives. (In contrast, specificity, not asked here, is the proportion of true negatives among those without the condition.)