In a cohort study examining alcohol and liver cirrhosis, 400 heavy drinkers and 400 non-drinkers are followed for 10 years. Cirrhosis develops in 80 heavy drinkers and 20 non-drinkers. The attributable risk percent in the exposed group (AR%) is:
- A 75% ✓
- B 80%
- C 60%
- D 25%
Correct answer: A. 75%
Explanation
Incidence in exposed = 80/400 = 0.20; incidence in unexposed = 20/400 = 0.05. Attributable risk = 0.20 − 0.05 = 0.15. AR% in exposed = (AR / Incidence in exposed) × 100 = (0.15/0.20) × 100 = 75%. This indicates that 75% of cirrhosis cases among heavy drinkers is attributable to heavy drinking and would be prevented if heavy drinking were eliminated. The remaining 25% occurs at background rates.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.