Does the structure (tunneled vs. free-roam) and content (if-then plans vs. choosing strategies) of a brief online alcohol intervention effect engagement and effectiveness? A randomized controlled trial.

Despite the potential of brief online interventions for reducing alcohol consumption, their effectiveness may be compromised by low levels of engagement and the inclusion of ineffective behavior change techniques. To test whether (i) a tunneled version of an intervention (where the content is delivered in a prespecified order) leads to greater engagement and greater reductions in alcohol consumption than a free-roam version (where the content can be viewed in any order) and (ii) forming if-then plans linking strategies to cut down with high-risk situations leads to greater reductions in alcohol consumption than only choosing strategies to cut down. Participants (N = 286 university staff and students) were randomly allocated to one of four versions of a brief online alcohol intervention in a 2 (structure: tunneled vs. free-roam) by 2 (planning: strategies vs. if-then plans) factorial design. Engagement (pages visited, time) was recorded automatically. Alcohol consumption (weekly units) was assessed at baseline and 1- and 6-month follow-up. Participants who received the tunneled version viewed significantly more pages and spent significantly more time on the website than those who received the free-roam version. Significant reductions in alcohol consumption were observed at follow-up; however, neither the structure of the intervention nor planning had a significant effect on reductions in alcohol consumption. Tunneled online interventions can increase engagement, but this may not translate into greater changes in behavior. Further experimental research using factorial designs is needed to identify the key behavior change techniques to include in brief online interventions.