Do associations between drinking event characteristics and underage drinking differ by drinking location?

Objective: We investigated how associations between social and situational characteristics (number of people, adult supervision, group gender composition, group age composition, ease of alcohol access, and weekend) and underage drinking are moderated by the specific locations in which drinking occurs. Method: Using a case-crossover design and retrospective surveys, a sample of 385 adolescents (mean age = 16.5 years; 47.3% female) from 24 mid-size California cities reported the last time they drank alcohol in a specific location (restaurant, outdoors, home) and the last time they were at the same type of location without drinking, as well as characteristics of each drinking and nondrinking event (N = 1,096 events). Results: Results of multilevel regression models indicated that perceived ease of alcohol access was associated with drinking across all locations (adjusted odds ratios [aORs] = 2.11–2.75, all p < .01). Weekend (vs. weekday) increased the odds of drinking outdoors (aOR = 3.75, p < .001) and in the home (aOR = 4.37, p < .001), as did a lack of adult supervision (aOR = 1.70, p < .05 for outdoors; aOR = 1.64, p < .01 for home). Larger groups (aOR = 1.06, p < .001) and being with older people (aOR = 2.28, p < .001) increased the odds of drinking in the home only. Significant cross-level interaction effects between location and group size (aOR = 0.96; p < .001), group gender composition (aOR = 0.78, p < .05), group age composition (aOR = 0.70, p < .01), ease of alcohol access (aOR = 0.88, p < .05), and weekend (aOR = 0.66, p < .05) suggested that these predictors were less significant in outdoor locations compared with the home. Conclusions: Locations moderate the social and situational characteristics of events and are important for underage drinking. Results can inform targeted prevention efforts.