Close friends', parents', and older siblings' smoking: reevaluating their influence on children's smoking.

A number of longitudinal studies have explored the role of friends', parents', and older siblings' smoking in children's smoking acquisition. A reasonable implication of this previous research is that intervention efforts could be beneficially directed toward countering the potential influence of friends' and possibly older siblings' smoking but not parents' smoking. However, methodological limitations of this previous research motivated our reevaluation of the role of friends', parents', and older siblings' smoking in children's smoking. Close friends' smoking status was assessed when children were in 5th grade, whereas parents' and older siblings' smoking status was assessed when children were in 3rd grade. The outcome, children's daily smoking status, was assessed in 12th grade. The setting was 40 Washington state school districts that participated in the long-term Hutchinson Smoking Prevention Project. Participants were the 4,576 families for whom close friends', parents', and older siblings' smoking status as well as children's smoking status were available. The probability that each close friend's smoking influenced the child to smoke daily was 9% (95% CI = 6%-12%), the probability that each parent's smoking influenced the child to smoke daily was 11% (95% CI = 9%-14%), and the probability that each older sibling's smoking influenced the child to smoke daily was 7% (95% CI = 1%-13%). These results suggest that close friends', parents', and siblings' smoking were similarly important influences on children's smoking. Family-focused interventions could be a valuable future direction of prevention research.

Parental smoking cessation and children's smoking: mediation by antismoking actions.

The present study investigated whether parents' antismoking actions mediated the prospective relationship between parental smoking cessation and children's smoking. Smoking status of parents (predictor) was assessed when their children were in 3rd grade, parental antismoking actions (mediators) were assessed when their children were in 11th grade, and children's smoking status (outcome) was assessed when they were in 12th grade. In 20 Washington state school districts, data were collected from 1,600 children (49% female, 91% White) and from their parents. Results showed that children's odds of daily smoking were reduced by 39% (95% CI = 24%-51%) for those whose parents had quit smoking, compared with those whose parents were current smokers. Asking to sit in nonsmoking sections of public establishments was a significant (p<.01) mediator that explained 64% of the association between parental smoking cessation and children's smoking. However, not allowing smoking in the home and asking others not to smoke around them were not significant mediators (p = .10, and p = .06, respectively). In conclusion, asking to sit in a nonsmoking section of a public establishment substantially mediates the relationship between parental smoking cessation and children's smoking.