JMIR Publications

ABSTRACT

Background:

Tobacco smoking remains the leading cause of preventable death and disease worldwide. Digital interventions delivered through smartphones offer a promising alternative to traditional methods, but little is known about their effectiveness.

Objective:

Our objective was to test the effectiveness of Quit Genius, a novel digital therapeutic intervention for smoking cessation.

Methods:

A two-arm, single-blinded, parallel-group randomized controlled trial design was used. Participants were recruited via referrals from primary care practices and social media advertisements in the UK. 556 Adult smokers (aged ≥18 years), smoking at least five cigarettes a day for the past year were recruited. 530 were included for the final analysis. Participants were randomized to one of two interventions. Treatment consisted of a digital therapeutic intervention for smoking cessation consisting of a smartphone application delivering cognitive behavioral therapy content, one-to-one coaching, craving tools and tracking capabilities. The control intervention was Very Brief Advice along the Ask, Advise, Act model. All participants were offered nicotine replacement therapy for three months. A random half of each arm was assigned a carbon monoxide (CO) device for biochemical verification. Outcomes were self-reported via phone or online. The primary outcome was self-reported 7-day point prevalence abstinence at 4-weeks post quit date.

Results:

556 participants were randomized (treatment n=277, control n=279). The intention-to-treat analysis included 530 participants (n=265 in each arm; 11 excluded for randomization before trial registration, and 15 for protocol violations at baseline visit). By the quit date (an average 16 days after randomization) 89% (236/265) of those in the treatment arm were still actively engaged. At the time of primary outcome, 74% (196) of participants were still engaging with the app. At 4-weeks post-quit date, 45% (118) of participants in the treatment arm had not smoked in the preceding 7-days, compared to 29% (76) in control (risk ratio 1.55, 1.23-1.96, P = .0002; intention-to-treat, N=530). Self-reported 7-day abstinence agreed with CO measurement (CO <10 ppm) in 96% of cases (80/83) where CO readings were available. No harmful effects of the intervention were observed.

Conclusions:

The Quit Genius digital therapeutic intervention is a superior treatment in achieving smoking cessation four weeks post quit date compared to very brief advice. Clinical Trial: The trial was registered in the ISRCTN database on December 18, 2018 (https://www.isrctn.com/ISRCTN65853476).