A Randomized Trial of Parental Behavioral Counseling and Cotinine Feedback for Lowering Environmental Tobacco Smoke Exposure in Children With Asthma Results of the LET'S Manage Asthma Trial

Background: Secondhand tobacco smoke exposure impairs the control of pediatric asthma. Evidence of the efficacy of interventions to reduce children's exposure and improve disease outcomes has been inconclusive. Methods: Caregivers of 519 children aged 3 to 12 years with asthma and reported smoke exposure attended two baseline assessment visits, which involved a parent interview, sampling of the children's urine (for cotinine assay), and spirometry (children >= 5 years). The caregivers and children (n = 352) with significant documented exposure (cotinine >= 10 ng/mL) attended a basic asthma education session, provided a third urine sample, and were randomized to the Lowering Environmental Tobacco Smoke: LET'S Manage Asthma (LET'S) intervention (n = 178) or usual care (n = 174). LET'S included three in-person, stage-of-change-based counseling sessions plus three follow-up,phone calls. Cotinine feedback was given at each in-person session. Follow-up visits at 6 and 12 months postrandomization repeated the baseline data collection. Multivariate regression analyses estimated the intervention effect on the natural logarithm of the cotinine to creatinine ratio (InCCR), use of health-care services, and other outcomes. Results: In the sample overall, the children in the LET'S intervention had lower follow-up InCCR values compared with the children in usual care, but the group difference was not significant (beta coefficient = -0.307, P = .064), and there was no group difference in the odds of having > one asthma-related medical visit (beta coefficient = 0.035, P = .78). However, children with high-risk asthma had statistically lower follow-up InCCR values compared with children in usual care (beta coefficient = -1.068, P = .006). Conclusions: The LET'S intervention was not associated with a statistically significant reduction in tobacco smoke exposure or use of health-care services in the sample as a whole. However, it appeared effective in reducing exposure in children at high risk for subsequent exacerbations. Trial registry: ClinicialTrials.gov; No.: NCT00217958; URL: clinicaltrials.gov CHEST 2011; 139(3):581-590