Prevalence and risk factors associated with smoking among school children, Southern Brazil.

OBJECTIVE To estimate the prevalence of smoking among students and associated factors. METHODS Secondary data from the Vigescola Survey, conducted in the cities of Curitiba, Florianópolis and Porto Alegre (Southern Brazil) between 2002 and 2004, were used. Sample comprised 3,690 school children, aged between 13 and 15 years, and enrolled in the 7th and 8th grades of primary school and 1st grade of high school, in public and private schools. Weighted proportions and odds ratio (OR) were estimated and multiple logistic regression was used to analyze results. RESULTS Smoking prevalence rates were 10.7% (95% CI: 10.2;11.3) in Florianópolis, 12.6% (95% CI: 12.4;12.9) in Curitiba and 17.7% (95% CI: 17.4;18.0) in Porto Alegre. Risk factors associated with smoking among schoolchildren in Curitiba were: female sex (OR=1.49), smoking father (OR=1.59), smoking friends (OR=3.46), exposure to secondhand tobacco smoke outside the home (OR=3.26), and having some object with cigarette brand logos (OR=3.29). In Florianópolis, variables associated with smoking were: female schoolchildren (OR=1.26), having smoking friends (OR=9.31), exposure to secondhand tobacco smoke at home (OR=2.03) and outside the home (OR=1.45) and having seen advertisements on posters (OR=1.82). In Porto Alegre, variables associated with tobacco use among school children were: female sex (OR=1.57), aged between 14 years (OR=1.77) and 15 years (OR=2.89), smoking friends (OR=9.12), exposure to secondhand tobacco smoke at home (OR=1.87) and outside the home (OR=1.77) and having some object with cigarette brand logos (OR=2.83). CONCLUSIONS Smoking prevalence among school children aged between 13 and 15 years is high. Factors significantly associated with it and common to the three capitals were as follows: having smoking friends and being exposed to environmental smoke outside the home.