Note: The ratio of ratios measures the difference between the API group and assessment-only control in change in binge drinking frequency from baseline to follow-up 1. If the ratio of ratios is 1, there is no difference between the groups. If the ratio of ratios is below 1, the API had the desired effect, i.e., reduced the change in binge drinking frequency relative to control. In this figure, a nonzero slope is evidence of effect modification by the proposed moderator. P-values are for the moderator-by-API-by-follow-up-1 interaction.