The analytic plan called for the initial analysis to be the main effects of the medication group and OPRM1 genotype and, most importantly, their interaction on the primary outcome variables using two-way ANOVA. Subsequent exploratory analysis evaluated the role of DAT genotype alone, or interacting, with the OPRM1 genotype and medication group (three-way ANOVA). A similar plan was applied to other secondary variables and other variables of interest (SHAS, AUQ, BAES, riboflavin levels) where appropriate.
