Results of an observational intervention trial: A promising harm reduction approach for persons with mental health and substance use disorders

Abstract Background: Individuals with mental health and substance use disorders smoke at much higher rates and have lower quit rates than the general population. This observational study evaluated the impact of a novel harm reduction intervention model on tobacco use in this group. Methods: The intervention included weekly support and allowed participants to set personal change goals and to use any of seven “aids” (patch, lozenge, gum, e-cigarettes, varenicline, bupropion, snus) or to decline the use of aids. The support consisted of 24 weeks of brief counseling or "SWITCH It," (8 weeks of coaching on replacing cigarettes with e-cigarettes). Primary outcomes included salivary DNA methylation, breath carbon monoxide (CO), and self-reported cigarettes per day (CPD). Eligibility required fluency in English or Spanish, salivary DNA methylation score Results: Analyses included 270 eligible individuals. There were significant increases in salivary DNA methylation scores from baseline to 6 and 12 months, and reductions over 6 months in CPD and breath CO. More weeks using e-cigarettes was associated with greater reduction in CPD and CO, but not salivary DNA methylation. Fewer years of smoking was associated with greater reduction in CPD. Most (85%) participants chose to use e-cigarettes, followed by FDA-approved nicotine replacement; very few individuals elected to use medications or snus. Participants appreciated the flexibility, lack of pressure to stop smoking, easy access to pharmacotherapy, and longer-term nature of the behavioral support. Examining cessation based on COConclusions: While the results demonstrate some promise in reducing tobacco use, it appears that most individuals require a more sustained commitment on the part of behavioral systems to enhance continued tobacco reduction. Trial Registration: ClinicalTrials.gov #NCT04523948.