Figure 2: False Positive Rates of Contrasting Scenarios, Odds Ratio Between Exposure and Outcome=2.0, Derived From Lognormal Distribution Figure 2 illustrates the false positive rates (1-specificity) of two contrasting scenarios, each with an odds ratio between exposure (E) and outcome (Y) of 2.0. In the first scenario there is no association between Y and third variable (C) but there is an association between E and C. Exposed subjects have twice the probability of trait C as unexposed subjects. (Line CY is missing in Figure 1.) In the second scenario there is no association between E and C but trait C doubles the probability of outcome Y. (Line EC is missing in Figure 1.) All probabilities are derived from the lognormal distribution using empirical estimates from simulated data for parameter values.