Does making early evening social plans impact alcohol use outcomes over evening hours?

Puropse: This study examined associations of evening plans to engage in different social activities with drinking behaviors and negative consequences experienced over weekend evening hours among underage young adults.

Ecological Momentary Assessment (EMA) data were collected from underage youth (19-20 years) in California in 8 evenings over 4 successive weekends. At 6pm, participants reported their social (i.e., any social plans tonight) and contextual (i.e., planning to be outside own home tonight) evening plans and whether they planned to drink that evening. They subsequently reported alcohol use and negative consequences within the past two hours at 8pm, 10pm, midnight, and the next morning. We used mixed effects logistic and negative binomial models controlling for demographics, history of alcohol use, drinking motives, and weekend day. Analyses were based on data obtained from 230 participants who reported on 1469 evenings.

In about 37 % and 46 % of evenings in which participants reported having social plans or plans to be outside own home, they reported no plans to drink alcohol, respectively. Social evening plans were positively associated with subsequent alcohol use (OR=3.312, p < 0.001), the number of drinks consumed (IRR=2.009, p < 0.001), and the number of negative consequences experienced (IRR=1.526, p < 0.05), independent of plans to drink that evening. Having any social evening plans was positively associated with planned (vs. unplanned) drinking (OR=7.080, p < 0.001).

Social evening plans may be important determinants of drinking behaviors and negative consequences across evening hours among underage young adults. Results can guide future interventions to reduce heavier drinking and associated harms.