Changes in environmental tobacco smoke exposure and asthma morbidity among urban school children

Environmental tobacco smoke (ETS) exposure is associated with poor asthma outcomes in children. However, little is known about natural changes in ETS exposure over time in children with asthma and how these changes may affect health-care utilization. This article documents the relationship between changes in ETS exposure and childhood asthma morbidity among children enrolled in a clinical trial of supervised asthma therapy.

Data for this analysis come from a large randomized clinical trial of supervised asthma therapy in which 290 children with persistent asthma were randomized to receive either usual care or supervised asthma therapy. No smoking cessation counseling or ETS exposure education was provided to caregivers; however, children were given 20 min of asthma education, which incorporated discussion of the avoidance of asthma triggers, including ETS. Asthma morbidity and ETS exposure data were collected from caregivers via telephone interviews at baseline and at the 1-year follow-up.

At baseline, 28% of caregivers reported ETS exposure in the home and 19% reported exposure outside of the primary household only. Among children whose ETS exposure decreased from baseline, fewer hospitalizations (p = 0.034) and emergency department (ED) visits (p < or = 0.001) were reported in the 12 months prior to the second interview compared to the 12 months prior to the first interview. Additionally, these children were 48% less likely (p = 0.042) to experience an episode of poor asthma control (EPAC).

This is the first study to demonstrate an association between ETS exposure reduction and fewer EPACs, respiratory-related ED visits, and hospitalizations. These findings emphasize the importance of ETS exposure reduction as a mechanism to improve asthma control and morbidity. Potential policy implications include supporting ETS reductions and smoking cessation interventions for parents and caregivers of children with asthma. Research to identify the most cost-effective strategy is warranted.