Article · Wikipedia archive · Last revised Jun 1, 2026

Absolute risk

Absolute risk is the probability or chance of an event. It is usually used for the number of events that occurred in a group, divided by the number of people in that group.

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Jun 1, 2026
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Illustration of two groups of sixteen: one exposed to treatment, and one unexposed. Exposed group has four individuals with an adverse outcome. Unexposed group has eight individuals with an adverse outcome.
The group exposed to treatment (left) has 1/4 or 25% absolute risk of an adverse outcome (dark). The unexposed group (right) has 1/2 or 50% absolute risk of an adverse outcome. source ↗

Absolute risk (or AR) is the probability or chance of an event. It is usually used for the number of events (such as a disease) that occurred in a group, divided by the number of people in that group.1

Absolute risk is one of the most understandable ways of communicating health risks to the general public.2

In difference to absolute risk, the relative risk (RR) is the ratio of the probability of an outcome in an exposed group to the probability of the outcome in an unexposed group.

See also

See also

References

References

  1. Porta, Miquel, ed. (2014). A dictionary of epidemiology (PDF) (Six ed.). Oxford: Oxford University Press. ISBN 9780199976720. Retrieved 11 November 2017.
  2. Trevena, LJ; Davey, HM; Barratt, A; Butow, P; Caldwell, P (February 2006). "A systematic review on communicating with patients about evidence". Journal of Evaluation in Clinical Practice. 12 (1): 13–23. doi:10.1111/j.1365-2753.2005.00596.x. PMID 16422776.
Further reading

Further reading