relative risk


Health Economics

  • (written as Relative Risk)
    A ratio of two risks, usually the chance of developing a disease if exposed to particular risk factors divided by the chance of developing it if one is not so exposed, or the ratio of risk in an experimental arm in a trial (E) to the risk in the control arm (C). It is used in randomized clinical trials and cohort studies and is calculated as E / C. Relative risk is often abbreviated to RR.
  • synonymHazard Ratio
  • synonymRelative Hazard
  • synonymRisk Ratio


  • noun a measure of the likelihood of developing a disease for people who are exposed to a particular risk, relative to people who are not exposed to the same risk. For example, the relative risk of myocardial infarction for oral contraceptive users is 1.6 times that of non-users.