Advising parents of asthmatic children on passive smoking randomised controlled trial

Objective. To investigate whether parents of asthmatic children would stop smoking or alter their smoking habits to protect their children from enviro nmental tobacco smoke. Design. Randomised controlled trial. Setting. Tayside and Fife, Scotland. Participants. 501 families with an asthmatic child aged 2-12 years living w ith a parent who smoked. Intervention. Parents were told about the impact of passive smoking on asth ma and were advised to stop smoking or change their smoking habits to prote ct their child's health. Main outcome measures. Salivary cotinine concentrations in children, and ch anges in reported smoking habits of the parents 1 year after the interventi on. Results. At the second visit, about 1 year after the baseline visit, a smal l decrease in salivary cotinine concentrations was found in both groups of children: the mean decrease in the intervention group (0.70 ng/ml) was slig htly smaller than that of the control group (0.88 ng/ml), but the net diffe rence of 0.19 ng/ml had a wide 95% confidence interval (- 0.86 to 0.48). Ov erall, 98% of parents in both groups still smoked at follow up. However, th ere was a non-significant tendency for parents in the intervention group to report smoking more at follow up and to having a reduced desire to stop sm oking. Conclusions. A brief intervention to advise parents of asthmatic children a bout the risks from passive smoking uas ineffective in reducing their child ren's exposure to environmental tobacco smoke. The intervention may have ma de some parents less inclined to stop smoking. Ifa clinician believes that a child's health is being affected by parental smoking, the parent's smokin g needs to be addressed as a separate issue from the child's health.