BACKGROUND
Nondaily smoking is a widespread, increasingly prevalent pattern of use. To date, no effective treatment approach for nondaily smoking has been identified.
OBJECTIVE
To conduct an unblinded randomized controlled trial to evaluate proof-of-concept markers of the Smiling instead of Smoking (SiS) app, a smoking cessation smartphone app designed specifically for people who smoke less than daily, which provides smoking cessation tools within the framework of positive psychology.
METHODS
A total of 226 adults who smoke less than daily were recruited online, and asked to undertake a quit attempt while using assigned smoking cessation support materials, randomized (2/25/21-6/29/2022) to one of three materials: the SiS smartphone app vs. the National Cancer Institute (NCI)’s smartphone app “Quit Guide” (QG) vs. the NCI’s smoking cessation brochure “Clearing the Air” (CtA). All participants engaged in a 15-minute scripted onboarding phone-call, during which study staff introduced participants to their support materials, which they were to use for the next seven weeks. Follow-up online, self-assess surveys occurred 2, 6, 12, and 24 weeks after participants’ initially chosen quit date (i.e., one week after onboarding). The primary outcome for this study was self-efficacy to remain abstinent from smoking at treatment end, as measured by the Smoking Self-Efficacy Questionnaire (SEQ). Secondary outcomes assessed treatment acceptability (e.g., Client Satisfaction Questionnaire (CSQ-8), System Usability Scale (SUS)), treatment feasibility (e.g., number of days of app use, time spent using app, use of smoking cessation strategies), and secondary proof-of-concept efficacy outcomes (e.g., positive affect, craving, attitudes towards smoking). Smoking outcomes (i.e., 30-day point prevalence abstinence, smoking reduction) were also assessed.
RESULTS
Results indicated a significant effect of treatment on the primary outcome, where SiS participants (n=80) reported higher self-efficacy to abstain from smoking at the end of treatment than the two control groups (QG (n=75): p=.0219, Cohen’s d=0.40; CtA (n=71): p=.0072, d=0.50). This effect was also significant on both self-efficacy subscales (i.e., internal cues, external cues) with effect sizes ranging from d=0.34 to 0.50 across the pairwise comparisons. The SiS app group also reported lower craving (QG: p=.0053, d=-0.57; CtA: p=.0053, d=-0.57) and higher positive affect than QG (QG: p=.0121, d=0.44; CtA: p=.0514, d=0.38); attitudes towards smoking were largely similar across groups. Treatment acceptability was comparable across groups (all ps>0.05; d range 0.06-0.23). Treatment feasibility measures indicated that participants used the SiS app on 32 out of 49 days, for 35-40 minutes per week, resulting in greater use of smoking cessation strategies than QG (QG: p=.0429, d=0.38; CtA: p=.16, d=0.24).
CONCLUSIONS
These findings provide strong evidence for the conceptual underpinnings of the SiS app, and thereby provide compelling justification for conducting a large-scale RCT that can test the effectiveness of the SiS app on smoking cessation.
CLINICALTRIAL
NCT04672239
INTERNATIONAL REGISTERED REPORT
RR2-10.2196/40867
