TVEM results do not rely on p-values for their interpretation. Thus, our GxI results were evaluated for significance via the following steps. First, each regression coefficient (including both main effects and interactions) and its 95% confidence interval (CI) are estimated as a function of age. Second, these estimates are compared against a hypothesis of no effect (β=0) and are declared significant at ages when their 95% CIs do not include 0. Equation 1 shows the TVEM used in our analyses.
