Likelihood Ratio (LR) is defined as the likelihood of a certain test result that is expected in a patient with a target disease in comparison to the likelihood of presence of the same result in a patient without that disease. This ratio is employed to ascertain the quality of a diagnostic test and to ultimately help in the selection of appropriate test(s). Text Reference: https://www.cebm.ox.ac.uk/resources/ebm-tools/likelihood-ratios