In a trial, 12% of control patients and 8% of treated patients had the event. What is the number needed to treat?
Answer and explanation
Correct answer: B. 25
- Step 1: The absolute risk reduction is 12% - 8% = 4%.
- Step 2: NNT = 1 / ARR = 100 / 4 = 25.
Answer
25.
Why not the others: The NNT is the reciprocal of the absolute risk reduction, not of the relative risk or the treated-group risk.
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