ERICA: smoking is associated with more severe asthma in Brazilian adolescents.

ABSTRACT

OBJECTIVE: To investigate the association between smoking and asthma, and possible associated factors in Brazilian adolescents. METHODS: A cross-sectional, national, school-based study with adolescents aged 12-17 years, participants in the Study of Cardiovascular Risks in Adolescents (Estudo de Riscos Cardiovasculares em Adolescentes - ERICA). A total of 66,394 participants answered a self-administered questionnaire with questions about asthma, smoking, lifestyle and sociodemographic variables. Bivariate analysis between Current Asthma (CA) and Severe Asthma (SA) and the other study variables were performed using Chi-squared. Then, the crude and adjusted Prevalence Ratios (PR), and respective 95% Confidence Intervals (95% CI) of current asthma/severe asthma and smoking variables, corrected for sociodemographic and lifestyle variables, were estimated using generalized linear models with Poisson regression, logit link, and robust variance. RESULTS: The prevalence of current asthma and severe asthma were significantly higher in adolescents who were exposed to experimentation (current asthma PR=1.78, 95% CI 1.51-2.09; severe asthma PR=2.01; 95% CI 1.35-2.98); current smoking (current asthma PR=2.08, 95% CI 1.65-2.64; severe asthma PR=2.29; 95% CI 1.38-3.82); regular smoking (current asthma PR=2.25, 95% CI 1.64-3.07; severe asthma PR 2.41; 95% CI 1.23-4.73); and passive smoking (current asthma PR=1.47, 95% CI 1.27-1.67; severe asthma PR=1.66; 95% CI 1.19-2.32); these associations remained significant after adjustment. CONCLUSIONS: Asthma and smoking were significantly associated in Brazilian adolescents, regardless of the sociodemographic and lifestyle factors, notably in those with more severe disease.