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

To investigate the association between smoking and asthma, and possible associated factors in Brazilian adolescents. 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. 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. Asthma and smoking were significantly associated in Brazilian adolescents, regardless of the sociodemographic and lifestyle factors, notably in those with more severe disease. Investigar a associação entre asma, tabagismo e possíveis fatores associados em adolescentes brasileiros. Estudo transversal, nacional, de base escolar, envolveu adolescentes com 12 a 17 anos, participantes do Estudo de Riscos Cardiovasculares em Adolescentes (ERICA). Os 66.394 participantes responderam questionários autopreenchíveis com questões sobre asma, tabagismo, estilo de vida e dados sociodemográficos. Foram realizadas análises bivariadas entre asma ativa e asma grave e demais variáveis do estudo, com o uso de χ2. Em seguida, foram estimadas as razões de prevalência (RP) brutas e ajustadas e seus respectivos intervalos de confiança de 95% (IC 95%), entre asma ativa/asma grave e variáveis de tabagismo, corrigidas pelas variáveis sociodemográficas e de estilo de vida, através de