A new rapid diagnostic test for dengue is evaluated against a gold-standard PCR test in 200 suspected cases. Results: True positive = 80, False positive = 10, False negative = 20, True negative = 90. What is the specificity of the new test?

• A 80%
• B 88%
• C 75%
• D 90% ✓

Explanation

Specificity = True Negatives / (True Negatives + False Positives) = 90 / (90 + 10) = 90/100 = 90%. Specificity reflects the test's ability to correctly identify those who do NOT have the disease. A highly specific test is preferred when a false positive result would cause significant harm or unnecessary treatment.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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