University of North Carolina

"2 out of 3 .00 BAC"

Project Description and Program Evaluation

The University of North Carolina at Chapel Hill (UNC CH) is a public, four-year university with a total student enrollment of 24,180 (15,400 undergraduate and 8,780 graduate and professional students).

(Note: Much of the following text is drawn verbatim from the report: "Enhancing A Norms Program to Reduce High-Risk Drinking Among First Year Students" by Robert Foss, PhD, Shane Diekman, MPH, Arthur Goodwin, MA, and Christopher Bartley, MA.)

Background

To gain a clearer picture of drinking among UNC CH students, a field survey was conducted in the fall of 1997. The sampling procedure was designed to obtain a representative sample of students as they returned to their residences in the late evening. A unique feature of this survey was the collection of breath samples, allowing for a direct measurement of blood alcohol concentration (BAC). An important study finding was that two-thirds of students returned home with a zero BAC on the traditional "party" nights. This finding ran counter to reports in the national media that portrayed college student drinking as a rampant epidemic. Through a series of discussions with students, a primary message was developed that was clear and easily understood by students:

  • "Whether it's Thursday, Friday, or Saturday night, 2 out of 3 UNC students return home with a .00 blood alcohol concentration."
A multi-faceted approach was developed to integrate this message into the routine functioning of the entire campus. The resulting "2 out of 3" social norms program focused initially on first year students, who are being immersed in the campus culture for the first time. Subsequent efforts were expanded to reach the entire campus community. Program Evaluation (2003)

To determine the effectiveness of the 2 out of 3 program, additional field survey data were obtained from students during the fall semesters of 1999 and 2002. Since the 2 out of 3 program was initiated in the summer of 1999, the fall 1999 data reflect possible early effects of the program, while the 2002 data represent enduring changes that may have occurred as the result of a sustained program. The analyses examined data for 6,352 undergraduate students interviewed during 1997, 1999, and 2002. A breath alcohol measurement was obtained for 6,108 (96%) of these individuals.

Campaign Awareness, Understanding, and Believability
Awareness
  • In 1999, 72% of all respondents indicated that they had heard of the campaign, including 92% of first year students.
  • In 2002, 91% of all respondents indicated that they had heard of the campaign, including 92% of first year students.
Understanding
  • In 1999, 72% of all respondents understood the general meaning of the campaign, including 80% of first year students.
  • In 2002, 82% of all respondents understood the general meaning of the campaign, including 83% of first year students.
Believability
  • In 1999, 35% of respondents who heard of and understood the message found it to be believable, including 34% of first year students.
  • In 2002, 45% of respondents who had heard of and understood the message found it to be believable, including 51% of first year students.

These findings indicate high awareness of the 2 out of 3 campaign, even from the beginning. Although many students found the message difficult to believe, the percent of non-believers decreased noticeably from 1999 to 2002.

Measurement of Student Drinking

A number of changes in student drinking were observed over the course of the study. Some of the most noteworthy changes from 1997 to 2002 include the following:

General Alcohol Use
  • Any alcohol use on the night of the interview—determined by both self-report and direct BAC measurement—decreased from 1997 to 2002.
  • Among those drinking on the night of the interview, the mean number of self-reported drinks consumed decreased from 5.1 to 4.3.
Heavier Drinking
  • Among respondents who were drinking on the night of the interview, the proportion with a BAC above .05% decreased from 60% to 52%.
  • Using the traditional self-report criterion for heavy drinking (five or more drinks on at least one occasion in the past two weeks), the proportion of heavy drinkers decreased from 50% to 45%.
  • Self-reported frequent heavy drinking (5 or more drinks on 3 or more occasions in the past two weeks) decreased from 24% to 20%.
  • The percentage of respondents who could be classified as heavy drinkers (5 or more drinks) on the night of the interview decreased from 13.8% to 9.6%, effectively a 30% proportionate change.

These findings provide support for the effectiveness of the 2 out of 3 campaign in reducing student alcohol use on the UNC–CH campus.The high degree of awareness and understanding of the 2 out of 3 message among UNC–CH students indicates that the social norms program was successful in reaching its target audience.The increased believability of the campaign suggests that the primary message, which specifies that on "party" nights most students drink little, if at all, became more accepted as the reality of student drinking on campus. Finally, the decreases observed in both self-report and direct measures of student drinking suggest that social norm marketing programs can affect actual drinking behavior.

Project Funding Sources

Funding for this project was provided by:
  • The National Highway Traffic Safety Administration
  • The North Carolina Governor's Highway Safety Program
  • The U.S. Department of Education
  • The University of North Carolina's Division of Student Affairs

The BAC Survey

Sampling Procedure

Data were collected in the fall semesters of 1997, 1999, and 2002. Between early October and mid-November, teams worked approximately 20 nights during each wave of data collection. Interviewing began at 10 p.m. and ended at 3 a.m. Over the course of each survey period, all residences were visited repeatedly at different times of the week: both before and after midnight on weeknights (Monday through Wednesday), Thursdays, and weekends (Fridays and Saturdays).

The sampling procedure was designed to obtain a representative sample of students who were returning home in the evening. To do this, the campus was divided into four geographically distinct routes along which interview teams walked. These routes passed by every residence hall and Greek house on or near campus.

Three separate interview teams, consisting of a supervisor and three interviewers, worked on scheduled data collection nights. Starting locations on each interview route were randomly selected to ensure that no particular location was more likely than others to be used for interviewing. Teams moved continuously between locations, typically collecting data at a single location for no more that 10-15 minutes on a single visit.

Interviews were also conducted at five apartment complexes that, according to UNC–CH records, housed large concentrations of university students. At these locations, sampling and interviewing resembled techniques typically used in roadside surveys (See: Foss RD, Beirness DJ, and Sprattler K, "Seat Belt Use Among Drinking Drivers in Minnesota." American Journal of Public Health, 1994, 88(11):1732-1737.)

Interview Procedure

At each residence, interview teams randomly sampled individuals or groups who were either approaching or standing in front of the residence; those who were merely passing by were not eligible for selection. One member of the interview team approached selected groups/individuals and asked if they would do a brief interview. For groups of three or fewer, all who consented were interviewed. For larger groups, three individuals were randomly sampled. When possible, the team supervisor conducted brief interviews with remaining group members. Interviewers and their respondents stepped away from any other individuals in the area to maintain confidentiality.

Interviews took approximately 5 to 6 minutes to complete and requested information about students' activities during the night, drinking (where, when, what, how much), their perceptions about alcohol use among students, and their knowledge of the 2 out of 3 campaign.

At the conclusion of the interview, respondents were asked to provide a breath sample, which was taken and analyzed using a portable breath test device, the Lion S-D2 Intoxilyzer. Interviewers then showed respondents their BAC readings and provided a brief explanation of the risks associated with any non-zero BAC level. Persons who declined to be interviewed were asked if they would simply provide a breath sample and many did so.

At apartment complexes, vehicles entering the parking lot were motioned to stop. Interviewers introduced themselves and asked if anyone in the vehicle was a UNC–CH student. If a student was present, that person(s) as well as the driver (if a non-student) was interviewed while they remained in their vehicles.

Marketing Methods Employed and Primary Normative Messages

As with most social norms programs, posters featuring factual evidence about student drinking were the primary mechanism used to establish an enduring presence for accurate information about local student drinking norms. New 2 out of 3 posters were created each year. While developing the posters, student feedback was solicited to determine how best to frame potential messages. Prototype materials were pre-tested with students to ensure the message was clear and was understood to mean what was intended. Using a new poster each year helped to keep the message delivery fresh, thereby reducing the possibility that students would tune out the information as outdated in subsequent years.

Primary Normative Messages

Marketing Methods Employed

Posters and zipper pulls with the message "2 out of 3 .00 BAC." In addition, numerous cash incentives were offered as a way to encourage students to know and retain the normative message, and to spread the word about it. For example, every week the "prize team" randomly selected student residence hall rooms, awarding $50 to those students with a poster hanging somewhere inside their room. (During spring semesters the poster reward was increased to $100.) In addition, campus residents were offered a zipper pull with the normative message on it at the beginning of the fall 2001 semester. Ever week the "prize team" randomly stopped students on campus and awards $5 to those displaying this pull on something they were carrying.

Project Co-Directors

Robert D. Foss, Ph.D.
University of North Carolina Highway Safety Research Center
CB# 3430, Chapel Hill, NC 27599
Tel 919/962-8702
Fax 919-962-8710
[email protected]

Sara Latta
University of North Carolina Highway Safety Research Center
CB# 3430, Chapel Hill, NC 27599
Tel 919/962-7419
Fax 919-962-8710
[email protected]

Further Information

UNC's 2 Out of 3 .00 BAC Campaign
Contents of this site include:
  • Details of the 1997 and 1999 breathalyzer study conducted at UNC
  • Online Social Norms Trivia Contest with cash giveaway incentive
  • Social Norms Poster with cash giveaway incentive

"BACs of University Students Returning Home at Night." by R.D. Foss, K.S. Holladay, C.L. Bartley, and L.M. Marchetti. A paper presented at the proceedings of the 15th International Conference on Alcohol, Drugs, and Traffic Safety. Borlänge, Sweden: Swedish National Road Administration, 2000. (Note: This is an Adobe Acrobat file.)
   This paper reports the methods and results of the initial, 1997 breathalyzer study conducted at the University of North Carolina. Of particular interest are the data for actual student BACs by time of week and the BACs of students by mode of arrival back home.

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