Background/Objectives: In an interim analysis, we evaluated the effectiveness of two intervention online-delivered approaches (cessation versus moderation) at 12-month follow-up among the first UNATI trial participants.

Methods: Interventions were delivered by trained health professionals via quarterly conference calls (20-30 min each). Alcohol intake was assessed at baseline and at 12 months. Mean intake (g/day) with 95% confidence intervals (95%CI) was estimated using validated self-reported tools. Within-group changes from baseline to 1 year were calculated, and the between-group difference in 1-year change (cessation vs. moderation) was estimated by sex.

Results: A total of 6,537 participants were included (2,139 women; 4,398 men). Overall, mean intake at baseline was 20.8 g/day (95%CI: 20.1;21.5) in the cessation group and 20.5 g/day (95%CI: 19.8;21.1) in moderation group. At 12 months, data were available for 1,170 participants included in this analysis. Average alcohol intake relatively decreased > 50% in the cessation arm (-10.9 g/day; [95%CI: -12.4;-9.5]) and also decreased (> 20% relatively) in the moderation arm (-4.7 g/day; [95%CI: -5.9;-3.5]), yielding a between-group difference in 1-year change of -6.2 g/day (95%CI: -8.1;-4.3; p < 0.001). In women, intake decreased from 15.6 to 6.3 g/day in the cessation arm (change -10.4; [95%CI: 12.9;-7.9]) and from 16.2 to 12.2 in moderation (-5.1 g/day; [95%CI: -6.5;-3.5]), with a between-group difference of -5.4 g/day (95%CI: -8.2;-2.5; p < 0.001). In men, intake decreased from 23.4 to 11.6 g/day in cessation (11.2;[95%CI: -13.1;-9.4]) and from 22.6 to 18.5 g/day in moderation (-4.6 g/day; [95%CI: -6.2;-2.9]), with a between-group difference of -6.6 g/day (95%CI: -9.1;-4.2; p < 0.001).

Conclusions/Recommendations: Both intervention strategies were effective in reducing average alcohol intake after 12 months, with substantially greater reductions in the randomized cessation arm. These findings support implementation of structured alcohol-reduction interventions.