Discussion
tobacco-related diseases, smoking reduction, Cancer
RECRUITMENT, CANCER
In this registered randomized controlled study, structured by a 2-week intervention period preceding a voluntary planned smoking quit date, we tested the effect of an app-based mindfulness training intervention compared with an attention control on smoking behavior during a 28-day quit attempt period. The trial results suggest that among the sample participants who opened apps at least once (a single dose), the app-based mindfulness training group showed an advantage on proportion of total days abstinent during a quit attempt period. The model estimated advantage of app-based mindfulness training on 7-day point-prevalence abstinence at the last week of assessment (week 4 of the quit period), however, did not reach statistical significance. In practical terms, our model estimated that it would require about 10 smokers willing to quit in the context of a trial to produce 1 successful complete 7-day (point-prevalence abstinence) abstinence case by week 4 of a quit attempt period. Further, the app-based mindfulness training group showed an advantage with respect to fewer average number of cigarettes smoked per day across the quit period. This pattern of results was initially promising, especially given that the Headspace app used in the app-based mindfulness training group is already fully developed, available to the public, and can be accessed by people in remote settings. Although the evidence yielded from this trial is limited for interpreting complete 7-day point-prevalence abstinence at week 4 of a quit attempt, our results are more promising for smoking reduction, which is considered an important harm-reduction strategy to reduce exposure to the carcinogenic properties of cigarette smoke and for the prevention of tobacco-related diseases (To address a gap in the field, we also used a data-driven approach to assess the number of study app sessions completed in relation to the proportion of days abstinent to attempt to decipher a target number of app sessions that might be productive for future studies using this mindfulness app or similar app types. This tentative finding suggests that among the sample participants who completed more than 20 app sessions, the average proportion of days abstinent in the app-based mindfulness training group was more than double that of controls (56% vs 36%, respectively). If this descriptive finding maintains generality for other samples, it offers users a clear goal of completing 20 app sessions, which equates to about 3.5 hours of commitment across 14 days. This finding is helpful to research and practice domains given that concrete recommendations for dosing mindfulness training are not well established, especially when delivered by app (We presumed that mindfulness meditation is the independent variable to function on smoking behavior as the dependent variable given that our selected attention control mirrors the intervention package on daily time exposure to digital educational content, study protocols, staff contacts, assessments, monitoring, and compensation schedules. All participants also received the self-administered smoking cessation workbook developed by the National Cancer Institute to hold constant the existing minimum standard of support offered to the public at no cost. Thus, there is a basic level of quit smoking education offered to all participants in the trial, including the education offered to all participants during our single motivational interview session at baseline, conducted by our trained research staff. We suspected that adding an app-based mindfulness training intervention assigned daily, twice per day, for 2 weeks offered a preparatory period to practice mindfulness training and gain skills in avoiding a response to fluctuating states, including aversive states associated with not smoking and deprivation of tobacco and/or nicotine. We specifically selected the Headspace app for the mindfulness training group because it focuses on guided meditation content not adapted for smoking cessation to determine whether a generalized mindfulness training app offers a benefit beyond what has previously been found for mindfulness training programs specifically adapted to smoking (Our findings suggest that mindfulness training offers a benefit without being specific to smoking behavior. A future study comparing a generalized mindfulness training app, such as Headspace, with smoking-specific mindfulness training intervention packages appears to be warranted at this time to determine the level of equivalence in their effects on smoking outcomes. Smokers could have the choice to select either the general mindfulness training or mindfulness training focused on smoking, depending on their preference and tolerance for educational material on smoking.The design characteristics of this randomized controlled trial contribute to the general strength of our study. For example, our remote research protocols for recruitment, interviewing, and surveying can be replicated at relatively low cost in future studies designed to examine longer periods of mindfulness training or mindfulness training combined with pharmacotherapy, such as nicotine replacement therapy. In support of this future aim, previous studies have identified telehealth approaches (eg, delivery of quit-smoking counseling by telephone) combined with nicotine replacement therapy to be a cost-effective strategy for cessation in clinical settings (Fourth, given the nature of the behavior intervention, which included practice and skill development, participants became aware of their study group content immediately following trial enrollment, which is a ubiquitous artifact of behavior intervention research. Unblinded study group content in this way can differentially reinforce participant adherence to select or preferred study interventions and protocols. Fifth, participants received compensation after the intervention period for the number of app session they completed, which may have increased their motivation to complete sessions. The total possible incentive amount was small ($2.50 per session), however, and compensation was not paid until the end of the intervention period. Compensation schedules were the same in both study groups. Sixth, the post-quit date follow-up period did not include assessment of additional app use or sustained abstinence at 3 and 6 months. This limited follow-up period masked the potential to detect lagged effects on smoking, effects that increase or decrease over time, and null effects that persist over time. Finally, our ITT analysis, which modeled the 7-day point-prevalence abstinence outcome, could be underpowered, as the actual missing data at the final 7-day point-prevalence abstinence period was 19% (162/200), which was higher than the expected 10% (180/200) we used in our pretrial power analysis.In summary, we find that low-demand, daily, app-guided mindfulness training with Headspace for the 2 weeks leading up to a planned quit date shows an empirical advantage over an attention control that includes basic education for smoking cessation, resulting in fewer days smoked and fewer cigarettes smoked in a sample of regionally diverse adults willing to make a quit attempt. These findings have implications for the use of commercially available mindfulness training apps that can be widely disseminated by health workers to potentially reducing exposure to the carcinogenic properties of inhaled cigarette smoke.