This cross-sectional study utilized participant interviews on-site at a large, alcohol-themed event to capture real-time data.
Data were collected during the Mifflin Street Block Party in May 2012. This event had approximately 5,000 attendees, most of whom were college students. This event was an ideal environment in which to study drinking behavior and SNS use in real-time, as it had a significant social media presence with 7,959 “likes” on the event's Facebook page as of November 1, 2012 . Study procedures were approved by the Institutional Review Board at the University of Wisconsin-Madison.
Participants were emerging adults attending the street festival. Inclusion criteria limited participants to those between the ages of 18 and 23 years. Persons who appeared to be heavily intoxicated were not approached.
During the street festival, between 12 pm and 5 pm, 7 research assistants (age > 21) were present at the MSBP in 5 different locations. The research assistants were trained to use a standardized protocol for data collection. The data collectors selected and approached individuals and asked if they were interested in participating in a brief interview about social media and alcohol use. After a script was read, interested individuals provided oral consent. Data collectors read interview questions to the participants and recorded their responses using pen and paper. The interview lasted approximately 5–10 min.
Rather than asking participant age directly, age was assessed as a yes/no response to the question “Are you between the ages of 18 and 23?” in order to avoid disclosures of underage drinking. The interviewer then assessed gender.
To assess alcohol consumption, the interviewer asked the participant if he/she had been drinking any alcohol that day. Participants who indicated they had been drinking were asked: “What time did you begin drinking today?” and “How many drinks have you had so far?” The interviewers recorded the time the interview took place so that the duration of drinking could be calculated.
All participants who indicated that they had been drinking were asked about SNS use. To assess SNS use, drinkers were asked: “Have you used Facebook since you started drinking today?” and “Have you used Twitter since you started drinking today?” Finally, to assess patterns in whether SNS are used for planning safe transportation we asked all participants: “Do you plan to use Facebook or Twitter to arrange transportation home tonight?”
Participants received a small (0.5 L) bottle of water as an incentive for participation.
Drinking duration was calculated by subtracting the reported time that drinking began from the time at which the interview was conducted. The rate of drinking was obtained by dividing the number of reported drinks by the duration of drinking. We multiplied the hourly rate by 2 in order to obtain an estimate of heavy episodic drinking that was in line with g criteria from the National Institutes of Alcoholism and Alcohol Abuse (NIAAA), defining heavy episodic drinkers as males who drank at a rate of 5 or more drinks in two hours and females who drank at a rate of more than 4 drinks in 2 h  We categorized heavy episodic drinkers as those with a drinking duration of 2 or more hours and a rate greater than or equal to 5 (for males) or 4 (for females) drinks per 2 h.
All analyses were conducted using Stata 12 computer software. Analysis first involved calculating descriptive statistics (means and proportions) for all variables. Chi-square tests were used to assess differences in categorical variables by gender and status as a heavy episodic drinker. Fisher's exact test was used in instances where the expected values were less than 5 observations in at least one cell of the 2 × 2 table. T-tests were used to assess between-group differences for the continuous variables for drinking duration and number of drinks.