In a clinical trial where the control event rate is 20% and the experimental event rate is 10%, the Number Needed to Treat (NNT) is:
- A 5
- B 10 ✓
- C 20
- D 50
Correct answer: B. 10
Explanation
NNT = 1 / Absolute Risk Reduction (ARR). ARR = Control event rate − Experimental event rate = 0.20 − 0.10 = 0.10. NNT = 1/0.10 = 10. This means 10 patients need to be treated to prevent one adverse event. The Relative Risk Reduction = ARR/CER = 0.10/0.20 = 50%.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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