Question

In a screening test for diabetes mellitus, out of 1000 population, 90 were positive. The gold standard test was then done, in which 100 were positive. Calculate the sensitivity.

• A. 90/100
• B. 100/110
• C. 80/100
• D. 100/100

Hint:

Sensitivity = true positives / all diseased (true positives + false negatives).

Answer 1

The Correct Option is A

Step 1: Sensitivity is the ability of a screening test to correctly identify those who truly have the disease. It is calculated as \(\text{Sensitivity} = \frac{a}{a+c}\), where \(a\) is true positives and \(c\) is false negatives.

Step 2: The gold standard shows 100 people truly have diabetes. The screening test detected 90 positives, all assumed to be true positives, so \(a = 90\).

Step 3: The remaining diseased persons missed by the screening test are false negatives: \(c = 100 - 90 = 10\).

Step 4: Therefore \[\text{Sensitivity} = \frac{90}{90+10} = \frac{90}{100}.\] The correct answer is option A.