The college drinker's check-up: outcomes of two randomized clinical trials of a computer-delivered intervention

Abstract

The objective of the study was to evaluate the effectiveness of a computer-delivered intervention (CDI) to reduce heavy drinking and alcohol-related problems in college students in two randomized clinical trials. In Experiment 1, we randomized 144 students to either the CDI or an assessment-only control group with follow-ups at 1 and 12 months. In Experiment 2, we randomized 82 students to either the CDI or a delayed-assessment control group with follow-up at 1 month. In Experiment 1, participants in both groups significantly reduced their drinking at both follow-ups. Compared to the control group, the CDI group reduced their drinking significantly more at 1 and 12 months on three drinking measures at α < .05. Using a more conservative, Bonferroni-adjusted criterion yielded one significant difference in a measure of heavier drinking at the 1 month follow-up. The mean between-groups effect sizes were d = .34 and .36 at 1 and 12 months, respectively. Experiment 2. Compared to the delayed assessment control group, the CDI group significantly reduced (by the Bonferroni-adjusted criterion) their drinking on all consumption measures. These results support the effectiveness of the CDI with heavy drinking college students when used in a clinical setting. In addition, the significant reductions in typical drinking in the control group in Experiment 1 and not in Experiment 2 combined with comparable baseline characteristics suggests that the control group in Experiment 1 demonstrated assessment reactivity.

Figure 1

Flowchart of participant flow and follow-up, Experiment 1.

Figure 2

Flowchart of participant flow and follow-up, Experiment 2.

Figure 3

Means for Standard Drinks in a Typical Week. Squares denote Experiment 1, circles and triangles are used for Experiment 2. Solid lines denote Control conditions, dashed lines denote Treatment conditions. The assessment of Baseline drinking in the Experiment 2 Control condition was by a retrospective pretest.

Figure 4

Means for Peak BAC in a Typical Week. Squares denote Experiment 1, circles and triangles are used for Experiment 2. Solid lines denote Control conditions, dashed lines denote Treatment conditions. The assessment of Baseline drinking in the Experiment 2 Control condition was by a retrospective pretest.

Figure 5

Mean number of drinks in two heavier episodes in previous month. Squares denote Experiment 1, circles and triangles are used for Experiment 2. Solid lines denote Control conditions, dashed lines denote Treatment conditions. The assessment of Baseline drinking in the Experiment 2 Control condition was by a retrospective pretest.

Figure 6

Mean in two heavier episodes in previous month. Squares denote Experiment 1, circles and triangles are used for Experiment 2. Solid lines denote Control conditions, dashed lines denote Treatment conditions. The assessment of Baseline drinking in the Experiment 2 Control condition was by a retrospective pretest.