A screening test for a rare disease is introduced in a low-prevalence population. Sensitivity and specificity are both 95%. Most positive test

Question

A screening test for a rare disease is introduced in a low-prevalence population. Sensitivity and specificity are both 95%. Most positive test results are false positives despite strong test characteristics. Which of the following is the most likely explanation for this patient's findings?

Accepted Answer

Low disease prevalence reducing positive predictive value

Answer

High specificity causing more false positives

Answer

Randomization failure

Answer

Low sensitivity producing false positives

Answer

High disease prevalence increasing false positives

Positive predictive value — USMLE Step 3 MCQ

A screening test for a rare disease is introduced in a low-prevalence population. Sensitivity and specificity are both 95%. Most positive test results are false positives despite strong test characteristics. Which of the following is the most likely explanation for this patient's findings?