Event-level contextual predictors of high-intensity drinking events among young adults

Background: Drinking events are characterized by social and physical contexts that are associated with level of alcohol consumption. Ecologically valid data is needed to delineate aspects of the drinking context that are most likely to precipitate excessive alcohol consumption. Methods: We utilized event-level data from a longitudinal study that included repeated daily surveys administered in two 28-day bursts. Data from 341 college student past-month alcohol and cannabis users (Mage=19.79; 53 % women; 74 % White) produced a total of 4107 alcohol use days. Generalized linear mixed effects models were used to predict drinking level (moderate: 1-3/1-4 for women/men; heavy-episodic drinking (HED): 4-7/ 5-9; high-intensity drinking (HID), 8+/10+) by social (e.g., with friends) and physical (e.g., at a party) contexts. We conducted analyses for the first and last drink reported, controlling demographic and study characteristics. Results: Being at a party, friend's house, or with strangers at the last drink reported were associated with HID compared to HED, while being at home, alone, or with family were protective for HID. No first drink contexts were associated with HID relative to HED. Witnessing others who were intoxicated was consistently associated with HID. Conclusions: Social settings such as parties and those with intoxicated persons were associated with risk for HID. The context of drinks at the end of an event are salient signals of level of alcohol consumption. Preventive interventions, particularly those that deliver strategies in real time, should consider accounting for contextual risk factors to reduce harms associated with excessive alcohol consumption.