Epidemiology & Prevention USMLE Step 1 Practice Question
A 58-year-old male smoker with a 40-pack-year history presents with productive cough and dyspnea. Vital signs show BP 145/88, HR 98, RR 22, SpO2 88% on room air. A longitudinal study evaluates chronic bronchitis incidence: 90 per 10,000 among smokers versus 30 per 10,000 among nonsmokers. Spirometry shows reduced FEV1/FVC ratio. He denies orthopnea. Which calculation represents the attributable risk of smoking for chronic bronchitis development?
Answer choices
- A60 per 10,000Correct answer
- B30 per 10,000
- C20 per 10,000
- D120 per 10,000
- E90 per 10,000
- F75 per 10,000
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