Association between secondhand smoking in the home and respiratory morbidity in preschool children

Objective: Identifying the prevalence of secondhand smoking in the home and its association with morbidity and hospitalization from respiratory causes in preschool children. Method: This is a cross-sectional study conducted in five early childhood education centers at a public university in Sao Paulo. Sample size calculation was performed and the participants were randomly determined. Data were collected through questionnaires completed by family members or caregivers of 215 children. Chi-square and Student's t-test were used for the statistical analysis, using a 0.05 significance level. Results: The prevalence of secondhand smoke in the household was 15.3%. Bivariate analysis revealed that secondhand smoke in the household was associated with the occurrence of rapid breathing, subdiaphragmatic retractions in the past three months, and treated ear infections/otitis. Conclusion: A low prevalence of secondhand smoking in the home was found. Secondhand smoke was associated with a higher prevalence of respiratory symptoms and morbidity.