Secondhand tobacco smoke in children with asthma: sources of and parental perceptions about exposure in children and parental readiness to change.

Background: Secondhand smoke triggers childhood asthma. Understanding sources of exposure, parental beliefs about exposure, and readiness to change that exposure are important for designing smoke exposure reduction interventions.

Methods: As part of screening for a clinical trial of a smoke exposure reduction intervention, 519 smoke-exposed children 3 to 12 years old with asthma provided urine specimens for cotinine testing, and their primary caregivers completed questionnaires.