Highlight
- A tailored just-in-time adaptive intervention (Smart-T) significantly increased biochemically verified 7-day smoking abstinence at 26 weeks compared to a standard QuitGuide app in low-income adults.
- Smart-T users interacted more frequently with the intervention and rated it as more helpful than QuitGuide users.
- Both interventions were combined with nicotine replacement therapy, underscoring the added value of the adaptive smartphone support.
- No significant differences were observed for 30-day or continuous abstinence outcomes, indicating the need for further optimization of sustained cessation support.
Study Background and Disease Burden
Smoking remains one of the most pervasive and preventable causes of morbidity and mortality worldwide. Low-income populations bear a disproportionate burden, exhibiting higher smoking prevalence and facing considerable challenges in quitting. Economic constraints, environmental stressors, lack of access to tailored cessation resources, and unique triggers for smoking lapses compound these disparities. These barriers highlight an unmet need for innovative, accessible cessation interventions that can dynamically address individual risk factors to increase quit rates and reduce health inequalities.
Mobile health (mHealth) platforms offer promising avenues to tailor cessation interventions in real time, adapting support based on users’ momentary contexts and experiences. Just-in-time adaptive interventions (JITAIs) leverage smartphone ecological momentary assessments (EMAs) to deliver tailored, timely motivational messages and coping strategies when individuals are most vulnerable to relapse. This approach hypothesizes that personalized feedback and prompts, coupled with pharmacotherapy such as nicotine replacement therapy (NRT), will enhance cessation outcomes, particularly in low-income adults who face distinct psychosocial and environmental challenges.
Study Design
This randomized clinical trial, conducted from August 2019 to November 2023, enrolled 454 U.S. adults whose household incomes were below 200% of the federal poverty line. Participants smoked an average of 17.7 cigarettes daily and had a mean age of 52 years, with women comprising approximately 73% of the cohort.
Participants were randomized into two groups: one receiving the Smart-T smartphone intervention and the other receiving the National Cancer Institute’s QuitGuide intervention. Both groups received 27 weeks of follow-up and were provided with nicotine replacement therapy.
The Smart-T intervention delivered ecological momentary assessment-driven, tailored feedback and prompts encouraging NRT use at critical moments identified via frequent real-time self-reports. QuitGuide, in contrast, provided evidence-based smoking cessation content consistent with clinical guidelines but without real-time tailoring or adaptive messaging.
The primary endpoint was biochemically verified 7-day point prevalence abstinence at 26 weeks post-quit date. Secondary outcomes included 30-day point prevalence abstinence and continuous abstinence measures over the follow-up period. The statistical analysis involved multivariable logistic regression, conducted through both intention-to-treat and complete-case approaches.
Key Findings
Of the 454 participants, 225 were assigned to Smart-T and 229 to QuitGuide. The primary outcome showed a statistically significant improvement for Smart-T over QuitGuide. In the intention-to-treat analysis, 16.4% (37 participants) of Smart-T users were abstinent at 26 weeks versus 10.0% (23 participants) of QuitGuide users. The complete-case analysis reinforced this benefit with 23.1% vs. 14.3% abstinence respectively.
Adjusted analysis revealed that Smart-T users had 1.81 times higher odds of smoking abstinence than QuitGuide users (95% confidence interval, 1.03-3.18), indicating robust efficacy for the tailored intervention.
No significant differences emerged between groups in 30-day point prevalence abstinence or continuous abstinence outcomes, suggesting that while immediate post-intervention cessation improved with Smart-T, sustained abstinence long-term requires additional strategies.
Engagement metrics favored Smart-T significantly, with users interacting more frequently with the application and rating it as more helpful (correlation coefficient r = 0.21; P < .001). This increased engagement underscores the potential of personalized, adaptive digital tools to overcome barriers specific to socioeconomically disadvantaged smokers.
Safety outcomes were not explicitly detailed in the report, but the provision of nicotine replacement therapy consistent with guidelines mitigates concerns about adverse effects from pharmacotherapy.
Expert Commentary
This trial represents a crucial advance in targeting a vulnerable population often underrepresented in cessation research. By harnessing ecological momentary assessments and adaptive tailoring, Smart-T addresses the dynamic triggers of smoking relapse experienced by low-income adults, such as situational stress and cravings, in a manner that static interventions cannot.
The significant though modest increase in 7-day abstinence rates at 26 weeks, combined with enhanced engagement, supports the biological plausibility of real-time risk assessments enabling more effective behavioral intervention. That no significant gains were observed in longer-term or 30-day abstinence measures signals that cessation maintenance remains challenging and may require integration of extended support, peer or provider engagement, or adjunctive therapies.
Limitations include potential selection bias given the recruitment strategy and generalizability confined to adults with incomes below 200% of the federal poverty line. Additionally, the predominance of female participants may affect applicability to male smokers. Future research should explore scalability, cost-effectiveness, and integration into routine clinical practice.
These findings align with emerging evidence supporting digital health interventions as scalable, accessible tools to reduce tobacco use disparities. Their incorporation into tobacco control policies and cessation programs could amplify public health impact.
Conclusion
In summary, the Smart-T just-in-time adaptive digital intervention significantly improves short-term smoking abstinence rates among low-income adult smokers when paired with nicotine replacement therapy, compared to a standard guideline-based smartphone app. Its real-time personalized feedback mechanism increases user engagement and cessation success at 26 weeks, offering a promising strategy to address socioeconomic disparities in tobacco cessation.
Broader implementation of tailored digital health solutions like Smart-T could substantially advance public health goals by facilitating equitable access to effective cessation support. However, sustaining long-term abstinence remains a challenge that requires continued innovation and comprehensive care models.
References
1. Hébert ET, Kendzor DE, Vidrine DJ, et al. Just-in-Time Adaptive Intervention for Smoking Cessation in Low-Income Adults: A Randomized Clinical Trial. JAMA Netw Open. 2025;8(8):e2526691. doi:10.1001/jamanetworkopen.2025.26691
2. U.S. Department of Health and Human Services. Smoking Cessation: A Report of the Surgeon General. Atlanta, GA: Centers for Disease Control and Prevention; 2020.
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