Preliminary Outcomes of a Digital Therapeutic Intervention for Smoking Cessation in Adult Smokers: Randomized Controlled Trial

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 preliminary effectiveness of Quit Genius, a novel digital therapeutic intervention for smoking cessation. Methods A 2-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 United Kingdom. A total of 556 adult smokers (aged 18 years or older) smoking at least 5 cigarettes a day for the past year were recruited. Of these, 530 were included for the final analysis. Participants were randomized to one of 2 interventions. Treatment consisted of a digital therapeutic intervention for smoking cessation consisting of a smartphone app 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 3 months. Participants in a random half of each arm were pseudorandomly assigned a carbon monoxide 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 A total of 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 of 16 days after randomization), 89.1% (236/265) of those in the treatment arm were still actively engaged. At the time of the primary outcome, 74.0% (196/265) of participants were still engaging with the app. At 4 weeks post quit date, 44.5% (118/265) of participants in the treatment arm had not smoked in the preceding 7 days compared with 28.7% (76/265) in the control group (risk ratio 1.55, 95% CI 1.23-1.96; P<.001; intention-to-treat, n=530). Self-reported 7-day abstinence agreed with carbon monoxide measurement (carbon monoxide <10 ppm) in 96% of cases (80/83) where carbon monoxide 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 4 weeks post quit date compared with very brief advice. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN) 65853476; https://www.isrctn.com/ISRCTN65853476

CONSORT EHEALTH (V 1.6.1) Submission/Publication Form The CONSORT-EHEALTH checklist is intended for a thors of randomi ed trials e al ating eb-based and Internet-based applications/inter entions, incl ding mobile inter entions, electronic games (incl m ltipla er games), social media, certain telehealth applications, and other interacti e and/or net orked electronic applications. Some of the items (e.g. all s bitems nder item 5 -description of the inter ention) ma also be applicable for other st d designs.
The goal of the CONSORT EHEALTH checklist and g ideline is to be a) a g ide for reporting for a thors of RCTs, b) to form a basis for appraisal of an ehealth trial (in terms of alidit ) CONSORT-EHEALTH items/s bitems are MANDATORY reporting items for st dies p blished in the Jo rnal of Medical Internet Research and other jo rnals / scientific societies endorsing the checklist.
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Mandator reporting items are marked ith a red *. In the te tbo es, either cop & paste the rele ant sections from o r man script into this form -please incl de an q otes from o r man script in QUOTATION MARKS, or ans er directl b pro iding additional information not in the man script, or elaborating on h the item as not rele ant for this st d .

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Does your paper address subitem 5 xii? *  8b Type of randomisation details of any restriction such as blocking and block size 9 Mechanism used to implement the random allocation sequence such as sequentially numbered containers describing any steps taken to conceal the sequence until interventions were assigned 10 Who generated the random allocation sequence who enrolled participants and who assigned participants to interventions Doe o pape add e CONSORT bi em a Cop and paste rele ant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from our manuscript), or elaborate on this item b pro iding additional information not in the ms, or briefl e plain h the item is not applicable/rele ant for our stud Participants ere randomi ed 1:1 (treatment:control) using a block si e of four

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Cop and paste rele ant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from our manuscript), or elaborate on this item b pro iding additional information not in the ms, or briefl e plain h the item is not applicable/rele ant for our stud Participants ere randomi ed 1:1 (treatment:control) using a block si e of four

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Cop and paste rele ant sections from the manuscript (include quotes in quotation marks "like this" to indicate direct quotes from our manuscript), or elaborate on this item b pro iding additional information not in the ms, or briefl e plain h the item is not applicable/rele ant for our stud "Participants ere randomi ed 1:1 (treatment:control) using a block si e of four " "Researchers randomi ing participants ere blind to allocation until the had performed the randomi ation."       As a result of using this checklist do ou think our manuscript has impro ed Would ou like to become in ol ed in the CONSORT EHEALTH group