Regression estimates are presented in Tables 2 and 3, and full logit models for the purposes of calculating predicted probabilities are provided in online supplementary material. As shown in Table 2, there was a significant main effect of GABRA2 such that carrying the high-risk genotype was associated with a 33 % increase in the estimated odds of alcohol dependence (p < 0.01). This odds ratio did not change in magnitude or significance when control variables were added to the model (Model II), suggesting that GABRA2 had a direct effect on alcohol dependence rather than an indirect effect through marital status, income, or other covariates. Holding other covariates constant, being a woman (OR = 0.21, p < 0.001) was associated with a significant decrease in the estimated odds of alcohol dependence, as was being currently married (OR = 0.71, p < 0.01). Also, additional years of education (OR = 0.88, p <0.001) and household income (OR = 0.88, p < 0.01) were associated with lower odds of alcohol dependence.
