Relative risk

Relative risk compares the chance of an outcome in one group with the chance in another. A relative risk of 1 means no difference.

This term is specific to research interpretation and is defined on AnxietyResearch. Shrinktionary, the network's language layer, doesn't currently carry a canonical entry for it.

Relative risk, sometimes called risk ratio, is more intuitive than the odds ratio. It is the risk in one group divided by the risk in the other. A relative risk of 1.5 means the outcome is 50 percent more likely in the first group. A relative risk of 0.7 means it is 30 percent less likely. It's used in cohort studies and randomized trials, where actual risk can be measured directly.

Relative risk appears in trial results and in cohort studies of anxiety. It's easier to read correctly than an odds ratio, which is why many researchers and readers prefer it.

In a cohort study, 6 percent of one group develops an anxiety disorder over five years, compared with 3 percent of another. The relative risk is 2.0. The first group's risk is twice as high.

Relative risk hides the starting size of the risk. A relative risk of 2.0 sounds alarming, but if the baseline risk is tiny, doubling it is still a small absolute change. Always ask for the absolute numbers alongside the relative ones.