Biostatistics & Study Design USMLE Step 1 Practice Question
A 46 year old woman presents with progressive exertional dyspnea, lower extremity edema, and abdominal distention. Her pretest probability of pulmonary hypertension is estimated at 30%. A screening echocardiogram yields a positive result with a positive likelihood ratio of 4. A confirmatory test then returns positive with a second positive likelihood ratio of 5. Assuming independent tests, which of the following is the approximate final posttest odds of disease?
Answer choices
- A8.6Correct answer
- B4.3
- C20
- D0.86
- E2.0
- F6.0
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