JMIR Publications

ABSTRACT

Background:

Smartphone applications are a convenient, low-cost approach to delivering smoking cessation support to large numbers of individuals. Yet, the apps are susceptible to low rates of user engagement and retention.

Objective:

This study tested the efficacy of a new game module (called “Inner Dragon”) integrated into Smoke Free, a leading smoking cessation app with established efficacy. The primary outcomes measured user engagement with the app.

Methods:

A two-arm, parallel-group, randomized controlled trial was conducted in the US with 8-week follow-up. Adult individuals who smoked 1 or more cigarettes daily and planned to quit smoking within 7 days were recruited and randomized (N=500), with equal allocation. Both groups received free access to the original Smoke Free app with “core” features of its smoking cessation program (e.g., a diary and cravings log), and the treated group received additional access to the internal Inner Dragon game that incorporated several game mechanics designed to increase user engagement. User engagement outcomes were number of unique app sessions, average minutes per session, and days with a session. Measures of program adherence, self-reported and verified smoking abstinence, and app satisfaction were also assessed. The main analysis estimated the intent-to-treat effect of access to Inner Dragon on each outcome. Further analyses assessed effect modification by participant characteristics and the association of intensity of game use with program adherence and abstinence.

Results:

Overall, user engagement was greater for treated vs. control participants: with 5.3 more sessions of Smoke Free (mean 29.6, SD 36.5 vs. mean 24.3, SD 37.9; P=.06), 0.8 more minutes per session (mean 6.9, SD 5.4 vs. mean 6.1, SD 5.2, P=.047), and 3.4 more days with a session (mean 14.3, SD 15.3 vs. mean 11.9, SD=14.3, P=.03). Program adherence, based on number of times core features of the original Smoke Free app were used, was higher for treated vs. control participants (mean 29.4, SD 41.3 vs. mean 22.6, SD 35.6; P=.03). Self-reported 7-day and 30-day and verified 7-day point-prevalence abstinence at 8 weeks did not significantly differ by study group. Mean repeated 1-day prevalence of quitting was higher among the treated group vs. the control group (17.3%, SD 25.6 vs. 12.4%, SD 21.3; P=.01). App satisfaction and motivation to (stay) quit did not differ by study group. Higher intensity of game use was associated with increased program adherence and self-reported abstinence.

Conclusions:

Findings suggest that the Inner Dragon game increased user engagement and program adherence. Additional refinements to the game design may clarify whether the game increases abstinence rates. Overall, it is feasible to deploy games and gamification to enhance user engagement in existing smoking cessation interventions. Clinical Trial: The trial was registered at ClinicalTrials.gov (NCT05227027).