Risk factors associated to asthma in 6-7 year old schoolchildren of Rio de Janeiro, Brazil

Methods Cross-sectional study using the adapted and validated ISAAC Written Questionnaire for Asthma for telephone interview. The sample was the systematic random type without replacement for school classes and students. Data were collected by a polling company from May/ July 2010. Bivariate analyses between asthma ("wheezing in the last 12 months”) and the study factors were performed using odds-ratio (OR), confidence intervals of 95% (95%CI) and Chi-square test. Factors associated to asthma in a bivariate analysis were studied using logistic regression models. The adopted level of significance was 5%.