Research & Statistics
Number Needed to Treat (NNT) Calculator
The Number Needed to Treat is one of the most clinically useful statistics in evidence-based physiotherapy. It tells you how many patients need to be treated for one additional patient to benefit.
Formula
NNT = 1 / ARR. ARR = Control rate - Treatment rate
Normal Range
NNT=1: Perfect treatment | NNT=2-5: Very effective | NNT>10: Less effective
Clinical Use
Evidence-based physiotherapy practice, research interpretation, clinical decision making.
Use the Calculator
Enter patient values and get instant AI-powered clinical interpretation.