Risk factors for asthma in schoolchildren in Southern Brazil

Abstract

Background: Due to the high prevalence of recurrent wheezing in the pediatric population, it is important to be able to identify environmental risk factors that may affect the etiology of asthma in several regions.

Objective: to identify possible risk factors associated with asthma in children (9-12 years old) in Passo Fundo, Rio Grande do Sul, Brazil.

Material and methods: A total of 1003 school-age children were selected for the cross-sectional study by applying a standardized written questionnaire from the International Study of Asthma and Allergy, and a supplementary questionnaire (ISAAC phase II) was added to address personal, family and environmental factors. Of these, 125 children were excluded because they did not accept to do the skin prick test, resulting in a sample of 878.

Results: Independent risk factors associated with asthma were bronchiolitis before two years old [OR]=3.11; 2.23-4.33, current rhinitis [0R]=2.07; 1.43-3.0; sharing bedroom during the first year of life [OR]=2.03; 1.36-3.04; atopy [OR]=1,82; 1.26-2.50; use of paracetamol more than 12 times a year [OR]=1.68; 1.20-2.31; use of antibiotics in the first six months of life [OR]=1,57 1;13-2.17; maternal asthma [OR]=1.75; 1.05-2.78, having an indoor cat during the first year of life [OR]=1.73, 1.07-2.78; premature birth [OR]=1.60,1.02-2.50.

Conclusion: our results show that genetic backgrounds, environmental factors, premature birth, use of antibiotics before six months of life, using paracetamol once per month and the presence of co-morbidities such as rhinitis are the risk factors associated with asthma in Brazilian children.

Keywords: Asthma; Atopy; Children; Epidemiology; International study of asthma and allergies in childhood (ISAAC); Risk factor.