Exploring the Use of Smartphone Geofencing to Study Characteristics of Alcohol Drinking Locations in High-Risk Gay and Bisexual Men.

BACKGROUND: Geofencing offers new opportunities to study how specific environments affect alcohol use and related behavior. In this study, we examined the feasibility of using geofencing to examine social/environmental factors related to alcohol use and sexual perceptions in a sample of gay and bisexual men (GBM) who engage in heavy drinking and high-risk sex.
METHODS: HIV-negative GBM (N = 76) completed ecological momentary assessments for 30 days via a smartphone application and were prompted to complete surveys when inside general geofences set around popular bars and clubs. A subset (N = 45) were also asked to complete surveys when inside personal geofences, which participants set themselves by identifying locations where they typically drank heavily.
RESULTS: Approximately 49% of participants received a survey prompted by a general geofence. Among those who identified at least 1 personal drinking location, 62.2% received a personal geofence-prompted survey. Of the 175 total location-based surveys, 40.2% occurred when participants were not at the location that was intended to be captured. Participants reported being most able to openly express themselves at gay bars/clubs and private residences, but these locations were also more "sexualized" than general bars/clubs. Participants did not drink more heavily at gay bars/clubs, but did when in locations with more intoxicated patrons or guests.
CONCLUSIONS: Geofencing has the potential to improve the validity of studies exploring environmental influences on drinking. However, the high number of "false-positive" prompts we observed suggests that geofences should be used carefully until improvements in precision are more widely available.