For routine clinical use, Bayesian methodology typically takes several forms: Odds-likelihood formulation (calculation or nomogram) Tabular approach Odds-likelihood calculation If the pre-test probability of disease is expressed as its odds and because a test's LR represents odds, the product of the 2 represents the post-test odds of disease (analogous to multiplying 2 probabilities together to calculate the probability of simultaneous occurrence of 2 events): Pre-test odds × LR = post-test odds Because clinicians typically think in terms of probabilities rather than odds, probability can be converted to odds (and vice versa) with these formulas: Odds = probability/1 − probability Probability = odds / odds + 1 Consider the example of UTI as given in the table Distribution of Test Results of a Hypothetical Leukocyte Esterase Test in a Cohort of 1000 Women With an Assumed 30% Prevalence of UTI, in which the pre-test probability of UTI is 0.3, and the test being used has an LR + of 4.73 and an LR - of 0.34.