Drinking on campus: self-reports and breath tests

Abstract

Objective: Concern about excessive alcohol consumption by college students has been raised by surveys indicating that more than 40% of students are "heavy" drinkers. This definition is based on students' reports of consuming five or more drinks (four or more for women) on an occasion sometime during the past 2 weeks. The present survey examines the degree to which this 2-week 5+/4+ drink criterion characterizes a student's pattern of alcohol use, and whether a 5+/4+ criterion for a drinking occasion is a valid indicator of high blood alcohol concentration (BAC).

Method: Students (N = 856, 70% male) were interviewed as they returned home between 10 PM and 3 AM. Students reported their drinking of the past 2 weeks and of the night they were interviewed, then provided breath samples to determine their BAC.

Results: Among the students in the sample classified as "heavy" drinkers on the basis of self-reports, 49% had zero BAC on the night they were interviewed. Those who reported consuming 5+/4+ drinks the evening of the interview had a mean BAC <0.08%. The distribution of BACs in the entire sample showed 74.4% of students had a BAC of zero and 11.8% had a BAC <0.05%. Very high BACs (i.e., > or =0.15%) were rare (1.3%).

Conclusions: Self-reports of consuming 5+/4+ drinks on at least one occasion during the previous 2 weeks did not reliably identify a pattern of heavy drinking. Moreover, reports of 5+/4+ drinks on an occasion were not necessarily associated with high BACs.