Aims: The first prospective investigation of the extent to which parental smoking cessation predicts their children's daily smoking.
Design: Parental smoking status was assessed when children were aged 8/9 years and children's smoking status was assessed at age 17/18 years.
Setting: Twenty Washington State school districts in the control group of the Hutchinson Smoking Prevention Project.
Participants and measurements: Questionnaire data were gathered on 3012 children (49% female and 91% Caucasian) and both of their parents in a cohort with a 95% retention rate.
Findings: When both parents quit smoking, children's odds of daily smoking were reduced by 39% (95% CI = 15%,56%) compared to when both parents were current smokers.Furthermore, when both parents never smoked then children's odds of daily smoking were reduced by 71% (95% CI = 62%,78%).
Conclusions: Parental smoking cessation is associated with reduced risk of their children's daily smoking. Parents who quit still place children at substantially higher risk compared to parents who never smoked.