Interventions to reduce college student drinking: State of the evidence for mechanisms of behavior change

Abstract

Interventions to reduce college student drinking, although efficacious, generally yield only small effects on behavior change. Examining mechanisms of change may help to improve the magnitude of intervention effects by identifying effective and ineffective active ingredients. Informed by guidelines for establishing mechanisms of change, we conducted a systematic review of alcohol interventions for college students to identify (a) which constructs have been examined and received support as mediators, (b) circumstances that enhance the likelihood of detecting mediation, and (c) the extent of evidence for mechanisms of change. We identified 61 trials that examined 22 potential mediators of intervention efficacy. Descriptive norms consistently mediated normative feedback interventions. Motivation to change consistently failed to mediate motivational interviewing interventions. Multiple active ingredient interventions were not substantially more likely to find evidence of mediation than single ingredient interventions. Delivering intervention content remotely reduced likelihood of finding support for mediation. With the exception of descriptive norms, there is inadequate evidence for the psychosocial constructs purported as mechanisms of change in the college drinking literature. Evidence for mechanisms will be yielded by future studies that map all active ingredients to targeted psychosocial outcomes and that assess potential mediators early, inclusively, and at appropriate intervals following interventions.

Keywords: Alcohol prevention; College students; Mechanisms of change; Mediation; Systematic review.

Conflict of interest statement

Conflict of Interest

All authors declare that they have no conflicts of interest.

Copyright © 2015 Elsevier Ltd. All rights reserved.

Figures

Figure 1

Path diagram of mediation of intervention effects by a single mediator. The a path reflects the effect of the intervention on changes in the mediator, the b path, the effect of changes in the mediator on changes in the outcomes, the c path, the effect of the intervention on changes in the outcomes before accounting for the mediator, and the c’ path, the effect of the intervention on changes in the outcomes controlling for the effect of the mediator.