A nested case-control survey on respiratory health was undertaken among a random sample of French women from the E3N study. Data were available for 570 women (235 with current asthma and 335 without asthma history; 68 years old on average, 59% never smokers). Three estimates of domestic exposure were used: 1) self-reported, 2) using principal component analysis, 3) a composite score for sprays. Associations between domestic exposures and asthma were assessed by logistic regression, adjusted for age, educational level, BMI and smoking status. Analyses were further stratified on household help in order to evaluate a potential misclassification bias.
Among women without household help (n聽=聽325), a significant association was observed between weekly use of at least one spray and current asthma (OR [95% CI]: 1.86[1.04-3.33]). No association was observed among women with household help.
Weekly household use of cleaning sprays may have a deleterious effect on asthma. It is important to take into account household help to limit misclassification bias.