The Intergenerational Continuity of Smoking in a Population Sample

Introduction. Smoking is a major public health issue and engenders high societal costs. Across many countries, children of smokers have higher probabilities of smoking themselves. Yet, few intergenerational, longitudinal studies consider both parents’ smoking and test potential moderators. We aimed to examine whether maternal and paternal smoking predicted youths’ smoking trajectories , and to test their interactions with one another, with the child’s sex, and with the father’s contacts with the child.Methods. Participants were 1601 youths from the Quebec Longitudinal Study of Child Development, a representative cohort from Quebec, Canada. Parents self reported smoking frequency between youths’ 5 months and 12 years of age. Youth self reported smoking frequency from 12 to 25 years old. We computed youths’ smoking trajectories using latent class growth analysis. We conducted multinomial regressions to test the study questions, controlling for racial origin, sex, parents’ education, family income, and frequency of contacts with the father. Results. Youths followed one of three trajectories: non-smokers (62%), occasional smokers (23%), and smokers (15%). Both parents’ smoking independently increased the odds of youths’ following the smoker trajectory. Only mothers’ smoking increased the odds of youths’ following the occasional smoker trajectory. Among control variables, being a boy, being white, living in a family with insufficient income, and infrequent contacts with the father predicted a higher smoking trajectory. Only one interaction was found with child’s sex.Discussion. There is an intergenerational link between parents’ and youths’ smoking. Prevention efforts should target children with smoking parents and sociodemographic risk factors. IMPLICATIONS. This study shows that youths follow one of three smoking trajectories based on smoking frequency between 12 to 25 years old and that both parents’ smoking independently predict youths’ smoking trajectory. The results suggest that prevention efforts should target children with a smoking parent, boys, and children of families of lower socioeconomic backgrounds.Summary of ResearchYouths are at higher risk of regular smoking from adolescence through early adulthood when their parents smoked.