Day-Level Mediators of Change in Brief Motivational Intervention for Alcohol Use and Liver Health.

Background: Day-level motivation to limit drinking is theorized to be a proximal mechanism of change in motivational interviewing (MI) interventions targeting alcohol intake, but day-level evidence remains limited. This study examined whether brief MI with personalized biobehavioral feedback was associated with changes in daily drinking among adults with alcohol use disorder (AUD) and alcohol-associated liver disease (ALD), and whether day-level importance and confidence to limit drinking served as within-person mediators of change. Methods: Participants ( Results: Daily drinking outcomes declined during the pre-intervention period, with no significant intervention-day shifts or post-intervention trends. However, the intervention-day shift was associated with increased day-level importance of limiting drinking, and higher-than-usual importance and confidence in limiting drinking on a given day were associated with fewer planned and actual drinks and lower odds of any drinking and heavy drinking. The intervention-day shift exerted significant indirect effects on daily drinking outcomes through same-day increases in importance of limiting drinking. Conclusions: Intensive longitudinal data supported perceived importance of limiting drinking as a proximal day-level mediator of change in brief AUD/ALD interventions, suggesting that frequent, day-level reinforcement of the personal salience of drinking reduction may be a key intervention target.