Advising parents of asthmatic children on passive smoking: randomised controlled trial.

Objective A randomised controlled trial to investigate whether parents of asthmatic children would stop smoking or alter their smoking habits to protect their children from environmental tobacco smoke.

Participants 501 families with an asthmatic child aged 2–12 years living with a parent who smoked.

Intervention Parents were told about the impact of passive smoking on asthma and advised to stop or change their smoking habits to protect their child’s health.

Main outcome measures Salivary cotinine concentrations in children, and changes in reported smoking habits of the parents 1 year after the intervention.

Results One year after the baseline visit, a small decrease in salivary cotinine concentrations was found in both groups of children, but there was no significant difference between the groups. Overall, 98% of parents in both groups still smoked at follow-up. However, there was a nonsignificant tendency for parents in the intervention group to report smoking more at follow-up and to having a reduced desire to stop smoking.

Conclusions A brief intervention to advise parents of asthmatic children about the risks from passive smoking was ineffective in reducing their children’s exposure to environmental tobacco smoke. If a clinician believes that a child’s health is being affected by parental smoking, the parent’s smoking needs to be addressed as a separate issue from the child’s health.