Intermediate
Technical
IVT
number needed to treat
Statistical measure showing how many patients must receive treatment to prevent one adverse outcome.
Full Definition
Number needed to treat (NNT) is a key epidemiological measure that quantifies treatment effectiveness in cardiovascular prevention. It represents the number of patients who need to be treated for a specific period to prevent one additional bad outcome (such as heart attack or stroke). Lower NNT values indicate more effective treatments. For example, an NNT of 50 means treating 50 patients for the specified duration will prevent one additional cardiovascular event compared to no treatment or placebo.
Usage
Usage note: Lowercase except when abbreviated as NNT; hyphenate when used as compound adjective
In Context
- "The statin therapy had a number needed to treat of 67 for preventing one major cardiovascular event over five years." — Clinical trial analysis
- "Clinicians should consider both the NNT and patient preferences when discussing preventive therapies." — Shared decision-making guideline
Also known as
NNT
Contrasted with
number needed to harm
Don't confuse with
number needed to harm
relative risk reduction