Effect of a Tobacco Cessation Intervention Incorporating Weight Management for Adults With Serious Mental Illness: A Randomized Clinical Trial

Importance: Tobacco smoking drives markedly elevated cardiovascular disease risk and preventable death in persons with serious mental illness, and these risks are compounded by the high prevalence of overweight/obesity that smoking cessation can exacerbate. Guideline-concordant combined pharmacotherapy and behavioral smoking cessation treatment improves abstinence but is not routinely offered in community settings, particularly to those not seeking to quit smoking immediately. Objective: To determine the effectiveness of an 18-month pharmacotherapy and behavioral smoking cessation intervention incorporating weight management and support for physical activity in adults with serious mental illness interested in quitting smoking within 1 or 6 months. Design, Setting, and Participants: This was a randomized clinical trial conducted from July 25, 2016, to March 20, 2020, at 4 community health programs. Adults with serious mental illness who smoked tobacco daily were included in the study. Participants were randomly assigned to intervention or control, stratified by willingness to try to quit immediately (within 1 month) or within 6 months. Assessors were masked to group assignment. Interventions: Pharmacotherapy, primarily varenicline, dual-form nicotine replacement, or their combination; tailored individual and group counseling for motivational enhancement; smoking cessation and relapse prevention; weight management counseling; and support for physical activity. Controls received quitline referrals. Main Outcome and Measures: The primary outcome was biochemically validated, 7-day point-prevalence tobacco abstinence at 18 months. Results: Of the 298 individuals screened for study inclusion, 192 enrolled (mean [SD] age, 49.6 [11.7] years; 97 women [50.5%]) and were randomly assigned to intervention (97 [50.5%]) or control (95 [49.5%]) groups. Participants self-identified with the following race and ethnicity categories: 93 Black or African American (48.4%), 6 Hispanic or Latino (3.1%), 90 White (46.9%), and 9 other (4.7%). A total of 82 participants (42.7%) had a schizophrenia spectrum disorder, 62 (32.3%) had bipolar disorder, and 48 (25.0%) had major depressive disorder; 119 participants (62%) reported interest in quitting immediately (within 1 month). Primary outcome data were collected in 183 participants (95.3%). At 18 months, 26.4% of participants (observed count, 27 of 97 [27.8%]) in the intervention group and 5.7% of participants (observed count, 6 of 95 [6.3%]) in the control group achieved abstinence (adjusted odds ratio [OR], 5.9; 95% CI, 2.3-15.4; P <.001). Readiness to quit within 1 month did not statistically significantly modify the intervention's effect on abstinence. The intervention group did not have significantly greater weight gain than the control group (mean weight change difference, 1.6 kg; 95% CI, -1.5 to 4.7 kg). Conclusions and Relevance: Findings of this randomized clinical trial showed that in persons with serious mental illness who are interested in quitting smoking within 6 months, an 18-month intervention with first-line pharmacotherapy and tailored behavioral support for smoking cessation and weight management increased tobacco abstinence without significant weight gain. Trial Registration: ClinicalTrials.gov Identifier: NCT02424188.