Glossary · Methodology
Number needed to treat (NNT)
In short
The number needed to treat (NNT) states how many people must receive a treatment for one of them to benefit who would not have done so without it. It translates study results into a tangible number.
It is calculated from the absolute risk difference: 100 divided by the difference in percentage points. If a risk over five years falls from 5 to 3 percent, the NNT is 50 — 50 people are treated for five years, and one is spared as a result.
An NNT always applies to a time period and a group. With a high baseline risk it is small, in healthy people with low risk it is large, even if the relative effect is the same. The counterpart for harms is called the number needed to harm.
How many have to take it for one to get something out of it?
Where this comes up in the fact checks
- Semaglutide – From the event rates, an NNT of about 67 over 3.3 years can be calculated — with a relative reduction of 20 percent.
Sources
Related terms: Relative and absolute effect · Hazard ratio · Effect size
Information only, not medical advice. The BK-Score is a subjective assessment according to disclosed rules – not a scientific evaluation. Scoring rules