ethnicity), and mean differences indicating the difference in the mean trait value given the presence of the risk factor, and corresponding 95% confidence intervals (CIs), were computed on the additive scale using an identity link in SAS 9.3 (Spiegelman & Hertzmark, 2005) to remain consistent with interaction analyses. Similar means for the alcohol phenotypes were observed in the genotype groups with protective allele A (AA and AG), while phenotype means were higher in those without allele A (GG) (see Table 1). Therefore, the GG group was compared to those with genotypes AA or AG. The ADH1B-rs1229984 variable (GG vs. AA/AG) was not related to demographics (sex, age, and ethnicity).
