Aims and background: We conducted a population-based trial to evaluate the efficacy of an intervention aimed at preventing exposure of young children to parental tobacco smoke.
Methods: Of the 1142 eligible couples (parents of newborn babies), 1015 were recruited; the intervention was offered to 402 and not to 613 families.
Results: A strong association was found between social class and smoking behavior, in particular smoking during meals at home. The intervention itself had limited effectiveness in decreasing the number of smokers. The effect was stronger in mothers and in higher social groups. Among the "white-collar" families belonging to the intervention group, the proportion of mothers who stopped smoking was 3 times higher than in the control group (not statistically significant).
Conclusions: Educational interventions against smoking should be planned taking into account the difference in efficacy according to social class.