Alcohol Outlets Near Homes Vs. within Activity Spaces and Risks for Alcohol Consumption for Adolescents

Introduction: Ecological studies provide evidence that alcohol consumption is greater in areas with more retail alcohol outlets. Some individual-level studies also identify that living near alcohol outlets is related to increased consumption, providing preliminary evidence that the ecological observations may be explained by relationships at the individual-level. However, individuals’ locations vary across space over time, and an individual’s place of residence may be a poor measure of their actual exposure to alcohol outlets. The aim of this study was first to compare the number of alcohol outlets near individuals’ homes and their exposure to alcohol outlets in their activity spaces (i.e. the places people go during their daily activities), and then to assess whether these measures are differentially related to risks for alcohol consumption. We focus on adolescents because travel patterns are poorly understood and alcohol consumption increases dramatically for this age group.

Methods: We collected prospective data for 257 adolescents aged 14 to 16 years from 10 mid-sized cities around the San Francisco Bay Area. Participants were provided with a GPS-enabled smart phone for one month, which recorded latitude and longitude coordinates every 60 seconds, and received a link for an ecological momentary assessment (EMA) survey 6 times per week (Thursday to Saturday). We compared static counts of outlets near participants homes (e.g. within Census tracts, within ½ mile circular buffers) with the average number of outlets per hour to which they were exposed over the study month using bivariate correlations. We then constructed zero-inflated Poisson models to relate these measures of alcohol outlets to the count of EMA responses for which respondents reported drinking any alcohol.

Results: The counts of alcohol outlets near adolescents’ homes were poorly correlated with the outlets per hour within activity spaces (r < 0.4). Zero-inflated Poisson models identified that outlets per hour within activity spaces was significantly related to adolescents’ self-reported alcohol consumption. The static counts of outlets near homes were unrelated to alcohol consumption.

Conclusions: Adolescents who are exposed to more alcohol outlets report greater alcohol consumption, and these associations were stronger for outlets measured across the extent of an activity space rather than those present near their homes. These findings suggest preventive intervention that reduces adolescents’ exposure to alcohol outlets may reduce alcohol consumption, and that future studies should use spatially and temporally specific measures of exposure.