exposure ratio

https://doi.org/10.1351/goldbook.15698
In a case control study, value obtained by dividing the rate at which persons in the case group are exposed to a risk factor (or to a protective factor) by the rate at which persons in the control group are exposed to the risk factor (or to the protective factor) of interest.
Source:
PAC, 2007, 79, 1153. (Glossary of terms used in toxicology, 2nd edition (IUPAC Recommendations 2007)) on page 1221 [Terms] [Paper]