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?
- A)8.6GABARITO
- B)4.3
- C)20
- D)0.86
- E)2.0
Explicação
Pretest odds are 0.30/0.70 = 0.43. After 2 independent positive tests, posttest odds equal 0.43 × 4 × 5 ≈ 8.6. Serial testing multiplies odds by the likelihood ratios of each test, which markedly increases disease probability when both tests are strongly posit... Ver explicação completa e trilha adaptativa →