Influence of psychosocial factors on smoking cessation: longitudinal evidence from the Pro-Saude Study.

OBJECTIVE To evaluate the incidence of smoking cessation and its association with psychosocial factors. METHODS Data came from three consecutive waves of the Pro-Saude Study, a longitudinal study of non-faculty civil servants working at a university in Rio de Janeiro, Southeastern Brazil. Inclusion criteria were having participated in Phases 1 and 3 and being a smoker at baseline (Phase 1--1999). Those who had stopped smoking less than a year before the follow-up (Phase 3--2007) were excluded. The final study population consisted of 661 employees (78% of those eligible). Relative risks (RR) of smoking cessation were evaluated through Poisson regression with robust variance. RESULTS The cumulative incidence of smoking cessation in eight years of follow-up was 27.7%. Among the psychosocial factors evaluated in the multivariate analysis, only lack of experience of physical violence was associated with higher smoking cessation (RR = 1.67, 95%CI 1.09;2.55). CONCLUSIONS The incidence of smoking cessation was high, and the fact that associations were not found with most factors evaluated suggests that much of the effect found is due to the impact of public policies implemented in Brazil over the past decades. The association between no exposure to violence and higher incidence of smoking cessation draws attention to the importance of this factor in tobacco control policies.