Objective: Web-based smoking cessation interventions have high reach, but low effectiveness. To address this problem, we conducted a pilot randomized controlled trial of the first web-based acceptance and commitment therapy (ACT) intervention for smoking cessation. The aims were to determine design feasibility, user receptivity, effect on 30-day point prevalence quit rate at 3 months post-randomization, and mediation by ACT theory-based processes of acceptance.
Methods: Adult participants were recruited nationally into the double-blind randomized controlled pilot trial (N = 222), which compared web-based ACT for smoking cessation (WebQuit.org) with the National Cancer Institute's Smokefree.gov-the U.S. national standard for web-based smoking cessation interventions.
Results: We recruited 222 participants in 10 weeks. Participants spent significantly longer on the ACT WebQuit.org site per login (18.98 vs. 10.72 min; p = .001) and were more satisfied with the site (74% vs. 42%; p =.002). Using available follow-up data, more than double the fraction of participants in the ACT WebQuit.org arm had quit smoking at the 3-month follow-up (23% vs. 10%; OR = 3.05; 95% CI = 1.01-9.32; p = .050). Eighty percent of this effect was mediated by ACT theory-based increases in total acceptance of physical, cognitive, and emotional cues to smoke (p < .001).
Conclusions: The trial design was feasible. Compared with Smokefree.gov, ACT had higher user receptivity and short-term cessation, and strong evidence of theory-based mechanisms of change. While results were promising, they were limited by the pilot design (e.g., limited follow-up), and thus a full-scale efficacy trial is now being conducted.