Cited by 1,885Statistical Methods in Clinical TrialsMeta-analysis and systematic reviewsStatistical Methods in Epidemiology

The number needed to treat: a clinically useful measure of treatment effect

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Cook, Richard J, Sackett, David L·1995·BMJ

Abstract

The relative benefit of an active treatment over a control is usually expressed as the relative risk, the relative risk reduction, or the odds ratio. These measures are used extensively in both clinical and epidemiological investigations. For clinical decision making, however, it is more meaningful to use the measure "number needed to treat." This measure is calculated on the inverse of the absolute risk reduction. It has the advantage that it conveys both statistical and clinical significance to the doctor. Furthermore, it can be used to extrapolate published findings to a patient at an arbitrary specified baseline risk when the relative risk reduction associated with treatment is constant for all levels of risk.

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Crossref · 10.1136/bmj.310.6977.452

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24 of 24 references verified0 citation errors · 0 not checkable

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  • A low number needed to treat (NNT), between 1 and 10, is desirable as it minimizes the costs associated with treating many individuals to benefit just one.

    “A low NNT, between 1 and 10, is desirable as it minimizes the costs associated with treating many individuals to benefit just one.23,24”

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Authors
Cook, R. J., & Sackett, D. L.
Affiliations
  • University of Waterloo (CA)
  • John Radcliffe Hospital (GB)
Venue
BMJ
Publisher
BMJ
Published
1995-02-18
Volume
310
Issue
6977
Pages
452-454
ISSN
  • 0007-1447 (ISSN-L)
  • 0959-8138
  • 1468-5833
OpenAlex
W2111149452
Cited by
1,885
References
24
Citations by year
2026: 27 · 2025: 35 · 2024: 33 · 2023: 44 · 2022: 36 · 2021: 51 · 2020: 32 · 2019: 48 · 2018: 44 · 2017: 59 · 2016: 62 · 2015: 59 · 2014: 60 · 2013: 82 · 2012: 76
FWCI
52.22
Type
journal article
Language
en
Open access
Locations
  • BMJ (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
Keywords
number needed to treat, absolute risk reduction, relative risk reduction, relative risk, odds ratio, treatment effect measurement, clinical decision-making, risk-benefit assessment
MeSH terms
Cerebrovascular Disorders, Humans, Hypertension, Statistics as Topic, Odds Ratio, Randomized Controlled Trials as Topic, Treatment Outcome, Risk Assessment

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