BACKGROUND: The authors have previously reported an increased prevalence of asthma in Estevan, Saskatchewan (21.4%) compared with Swift Current, Saskatchewan (16.2%).OBJECTIVE: To determine the association between asthma and personal and indoor environmental risk factors in these communities.METHODS: A population-based cross-sectional study was conducted in January 2000. A questionnaire was distributed to school children in grades 1 to 6 for completion by a parent. Multivariate logistic regression was used to examine associations between various risk factors and physician-diagnosed asthma.RESULTS: Asthma was associated with respiratory allergy (adjusted OR [adjOR]=8.85, 95% CI 6.79 to 11.54), early respiratory illness (adjOR=2.81, 95% CI 1.96 to 4.03) and family history of asthma (adjOR=2.37, 95% CI 1.67 to 3.36). Several environmental factors varied with asthma by town. In Estevan, asthma was associated with home mould or dampness (adjOR=1.82, 95% CI 1.23 to 2.69) and was inversely associated with air conditioning (adjOR=0.56, 95% CI 0.37 to 0.85). The risk of asthma was increased if the child had previous exposure to environmental tobacco smoke from the mother in both communities (Swift Current: OR=1.87, 95% CI 1.06 to 3.30; Estevan: OR=2.00, 95% CI 1.17 to 3.43), and there was an inverse association with current exposure to environmental tobacco smoke from the mother in Estevan (OR=0.64, 95% CI 0.40 to 1.00). When multivariate analyses were stratified by sex, the relationship between home mould or dampness and asthma was most prominent in girls in Estevan.CONCLUSIONS: Despite a similar regional location, different risk factors for asthma were identified in each community. Local environmental factors are important to consider when interpreting findings and planning asthma care.
Environmental tobacco smoke and the risk of eczema symptoms among school children in South Africa: a cross-sectional study
