relative risk (RR)

The ratio (quotient) of the risk that an event will occur among the subjects exposed to a given factor and the risk that this event will occur among the subjects not exposed to this factor.

Note: A relative risk (RR) of 1 indicates that the risk is equal in the groups compared, an RR > 1 indicates that the factor increases the risk, and an RR < 1 indicates that the factor decreases the risk.

Syn.: risk ratio.