Contingency management for smoking cessation for individuals with overweight or obesity: A randomized controlled trial

Abstract

Background: Interventions for quitting smoking and weight control among individuals with excess weight are scarce. Our study evaluated the effectiveness of cognitive behavioral therapy (CBT) plus contingency management (CM) in this population, and examined whether CM for smoking cessation improved CBT treatment outcomes at end of treatment (EOT) and at 1-, 3-, 6-, and 12-month follow-ups (FU).

Methods: In an 8-week randomized clinical trial, 120 adults who smoke with overweight or obesity (54.16% females; M_BMI = 31.75 ± 4.31) were randomly assigned to CBT for both quitting smoking and weight control (n = 60) or the same treatment plus CM for smoking cessation (n = 60). Outcome variables were compared (i.e., treatment completion, smoking abstinence, weight change and secondary outcomes).

Results: At EOT, the CBT + CM group achieved 78.33% 7-day point-prevalence abstinence rates compared to 61.67% in the CBT group (p = .073), and rates declined over time (12-month FU: 18% vs 12%). Participants who attained abstinence weighed more compared to baseline at EOT (M_kg = 1.07; SD = 1.88) and over time (12-month FU: M_kg = 4.19; SD = 4.31). No differences were found between the two groups in outcome variables.

Conclusions: Both interventions were effective in promoting abstinence and reducing tobacco use over time. Combining CBT with CM for smoking cessation did not improve treatment outcomes in individuals with overweight or obesity compared to CBT only. Future studies should evaluate whether implementing CM for weight maintenance helps control post-cessation weight gain in this population.

Keywords: Cognitive behavioral therapy; Contingency management; Obesity; Overweight; Smoking cessation; Weight gain.