The attributable risk is an additional means of comparing both groups. It’s the incidence of disease in the exposed group that can be attributed to the exposure. In epidemiological studies, the number needed to harm is often abbreviated as NNH. It’s the inverse of the attributable risk, that is, 1 divided by the attributable risk.
An interactive version of this Chalk Talk episode can be found at:
www.amboss.com/us/auditor/statistics3