odds ratio

Syllable breakdown

Dictionary meaning

a statistical measure used in epidemiology and clinical research to quantify the association between an exposure and an outcome, calculated as the ratio of the odds of the outcome occurring in the exposed group to the odds of the outcome occurring in the unexposed group; an odds ratio of 1 indicates no association, greater than 1 indicates increased odds in the exposed group, and less than 1 indicates reduced odds; in case-control studies the odds ratio is the primary estimator of association because incidence cannot be directly calculated from the study design; when outcomes are rare, the odds ratio approximates the relative risk; the odds ratio is also produced by logistic regression models, making it the default association measure in multivariate analyses of binary outcomes across medicine, public health, and the social sciences