In unadjusted analyses in EAs, all three candidate phenotypes were associated with rs1229984 (χ2 p-values all < 10−40) (Table 2a and b, Figure 2d-f ). In ordered logit models adjusted for the first 10 PCs, sex, and age, the association was again strongest for age-adjusted mean AUDIT-C score, treated as an ordinal variable (p=4.38 × 10−49). The addition of AUDIT-C trajectories to the age-adjusted mean AUDIT-C score model did not significantly improve model fit (both pseudo R2=0.056, LRT=6.08; df=3; p=0.11). The addition of AUD diagnostic codes, however, improved discrimination (pseudo R2=0.057, LRT=77.54, df=1, p=1.30 e-18), again showing that mean AUDIT-C score and AUD diagnostic codes can be combined to obtain more information about alcohol-related risk. Comparing EAs with an age-adjusted mean AUDIT-C of 8 to those with a score of 0, the adjusted odds of having the rs1229984 minor allele was 0.48 (95% CI 0.31, 0.74) (Table 2b). Having an AUD independently reduced the odds by 0.68 (95% CI 0.62, 0.74). Having both an AUDIT-C score of 8+ and an AUD diagnosis compared to an AUDIT-C of 0 and no AUD diagnosis would reduce the aOR of the rs1229984 minor allele to 0.33 (data not otherwise shown).
