JMIR Publications

ABSTRACT

Background:

Theoretically informed by the Dynamic Model of Relapse, GamblingLess: In-The-Moment is a smartphone app-based Just-In-Time Adaptive Intervention (JITAI) that delivers tailored interventions in moments of cognitive vulnerability to people who want to quit or reduce their gambling. Specifically, it aims to reduce gambling symptom severity (primary distal outcome) through short-term reductions in the likelihood of gambling episodes (primary proximal outcome) by improving craving intensity, self-efficacy, or positive outcome expectancies (secondary proximal outcomes).

Objective:

The primary aim was to explore whether the delivery of a tailored intervention via GamblingLess: In-The-Moment, compared with no intervention, reduces the probability of a subsequent gambling episode (primary proximal outcome) and improves subsequent craving intensity, self-efficacy, and positive outcome expectancies (secondary proximal outcomes). Secondary aims included identifying the most beneficial intervention option, conditions under which the intervention is most effective, and how its effects change over the treatment period.

Methods:

A fully automated and blinded 28-day micro-randomized trial (MRT) was conducted with participants recruited via online convenience sampling. Participants self-reporting high craving intensity, low self-efficacy, and/or high positive outcome expectancies in ecological momentary assessments (EMAs; delivered via push notifications three-times daily) were randomly assigned to either a tailored intervention or a no intervention control condition. The intervention condition comprised three modules (Curbing Cravings; Tackling Triggers; Exploring Expectancies) targeting each of these cognitive processes. The no intervention control condition comprised a brief message of encouragement, but no intervention content. The MRT was supplemented with a within-group six-month follow-up evaluation to investigate longer-term treatment effects.

Results:

The sample comprised 192 participants (66.2% male; median age 35 years) who completed at least one EMA during the trial period. Overall, 5,116 EMAs were completed (compliance rate 31.7%). In the MRT, the tailored intervention was no more effective than no intervention in reducing subsequent gambling episodes (OR=1.05, 95%CI 0.79, 1.38, p=.74) or improving the secondary proximal outcomes. However, post-hoc supplementary analyses indicated improvements in craving intensity and self-efficacy when collapsing all EMAs across each day. Moreover, compared to the no intervention control condition, Tackling Triggers increased subsequent self-efficacy and Exploring Expectancies reduced subsequent positive outcome expectancies. There were also very large improvements in all secondary proximal outcomes across all intervention options immediately after an intervention activity. There were large improvements in gambling symptom severity (primary distal outcome) at the six-month follow-up evaluation (dz=-1.94, p<.001), with 66.5% of participants demonstrating clinically significant recovery or improvement. Finally, there were medium to large improvements in gambling frequency, expenditure, craving severity, self-efficacy, and positive outcome expectancies (secondary distal outcomes).

Conclusions:

This trial demonstrates promising findings but represents an early stage of gambling mHealth development and evaluation, with further research required to optimise the intervention to improve its effectiveness, efficiency, scalability, and user engagement. Clinical Trial: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12622000490774; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380757&isClinicalTrial=False