RESUMO
OBJECTIVES: This study aimed to identify factors associated with attempting to quit and successful smoking cessation in a population-based sample of Brazilian smokers. STUDY DESIGN: This is a prospective cohort study. METHODS: Data came from the first two waves of the International Tobacco Control Brazil Survey, conducted in 2009 and 2012/2013 in three cities: Rio de Janeiro, São Paulo, and Porto Alegre. Data were collected from 488 adults (aged ≥18 years) who smoked at Wave 1 and who were resurveyed at Wave 2. Crude and adjusted relative risks for two outcomes (making a quit attempt between Wave 1 and Wave 2 and successfully quitting by Wave 2) were estimated. Multivariable multilevel logistic regression models were used, whereby variables were added to the models in a series of blocks. RESULTS: Nearly two-thirds (65.6%) of smokers attempted to quit between waves, and 23.4% had quit at Wave 2. Intention to quit smoking at Wave 1 was the only variable associated with attempt to quit by Wave 2 (odds ratio [OR] = 2.85; 95% confidence interval [CI] 1.64-4.94; P < 0.001). Smokers of higher socio-economic status (OR high versus low = 1.80; 95% CI 1.05-3.10; P = 0.03) and lower nicotine dependence (OR low Heaviness of Smoking Index [HSI] versus high HSI = 1.94; 95% CI 1.10-3.43; P = 0.02) were more likely to successfully quit. The presence of another adult smoker at home was negatively related to successful quitting (OR = 0.50; 95% CI 0.26-0.94; P = 0.03). CONCLUSIONS: These results are generally consistent with prior research and have potential to inform governmental interventions to promote tobacco cessation, particularly among disadvantaged groups.