Objective: Urban children with asthma experience high rates of second hand smoke (SHS) exposure. The objective was to examine whether SHS exposure is associated with symptom frequency in children with poorly controlled asthma. Methods: Children were enrolled in a RCT to test the efficacy of an environmental control behavioral intervention versus an attention control group and followed over 12 months. SHS exposure assessed using salivary cotinine measurement. Frequency of child asthma symptoms, healthcare utilization, household smoking and caregiver daily life stress were obtained via caregiver report. Time of enrollment was recorded to assess seasonal factors. Symptom days and nights were the primary outcomes. Multivariable models and odds ratios examined factors that best predicted increased frequency of daytime/nighttime symptoms. Results: Children (n = 222) with a mean age of 6.3 (SD 2.7) years, were primarily male (65%), African American (94%), Medicaid insured (94%), and had poorly controlled asthma (54%). The final multivariable model indicated symptoms in the fall (OR 2.78; 95% CI 1.16, 6.52) and increased caregiver daily life stress (OR 1.13, 95% CI 1.02, 1.25) were significantly associated with increased symptom days when controlling for cotinine level, intervention status, child age and home and car smoking restrictions. Conclusions: There was no impact of SHS exposure on increased symptom frequency. High caregiver daily life stress and symptoms in fall season may place children with asthma at risk for increased day/nighttime symptoms. Close monitoring of symptoms and medication use during the fall season and intervening on caregiver life stress may decrease asthma morbidity in children with poorly controlled asthma.
Trial registration: ClinicalTrials.gov NCT01981564.
Keywords: Pediatric; asthma; second hand smoke exposure; caregiver stress.