A likelihood ratio expresses the odds, for instance, that a Johne’s disease test result at a given level would be expected in an animal infected with M. paratuberculosis as opposed to one not infected. LHR is a very powerful way to interpret test results when the test produces a quantitative result such as the ELISA S/P ratio. LHRs can only be defined by actual testing of large populations of truly infected and truly noninfected animals. This website provides a more comprehensive explanation of LHRs.
