OBJECTIVE: Unplanned drinking, or drinking that violates intentions to limit alcohol consumption, has been linked to significant alcohol-related consequences in college students
however, predictors and outcomes remain incompletely understood among other populations of young adults. This study identified person- and event-level predictors of unplanned drinking and explore the association of unplanned drinking with negative alcohol-related consequences in a racially and educationally diverse cohort of young adults. METHOD: A total of 938 young adults (aged 18-25
70 % female
60 % non-college
37 % Black) participating in a randomized trial testing text-message alcohol interventions completed ecological momentary assessments (EMA) reporting drinking intentions and alcohol consumption twice weekly for at least 4 weeks over a 14 week period. Controlling for intervention effects, mixed-effects models examined predictors of unplanned drinking days, and zero-inflated negative binomial regression models assessed the relationship between frequency of unplanned drinking and negative alcohol consequences at a 14-week follow-up. RESULTS: Participants reported alcohol consumption on 16.9 % of days when they had no plan to drink. Odds of unplanned drinking was higher for older age (adjusted Odds Ratio [aOR] = 1.06, p <
0.01), Black race (aOR = 1.25, p <
0.01), higher AUDIT-C score (aOR = 1.14, p <
0.001), and higher negative urgency score (aOR = 1.05, p <
0.01), weekends (aOR = 1.63, p <
0.001) and the presence of friends drinking (aOR = 9.37, p <
0.001). Compared to participants in the lowest unplanned drinking day category, those in the highest category showed a 26 % higher negative alcohol consequence rate ratio (RR = 1.26, 95 % CI [1.07, 1.48]). CONCLUSIONS: Unplanned drinking in young adults is strongly influenced by social context and individual risk factors. This behavior, when extreme, was associated with increased negative alcohol-related consequences. Interventions targeting impulsivity and peer influence may reduce unplanned drinking and mitigate its harmful effects.