An analysis of associations of having children with smoking prevalence and intensity using nationally representative survey data in Japan.

BACKGROUND: In Japan, the association with smoking status and having children after infancy has not been investigated. In this study, we examined the associations of having children with smoking prevalence and intensity using nationally representative survey data in Japan. METHODS: A cross-sectional study was conducted, and data on the Comprehensive Survey of Living Conditions in 2010, 2013, 2016, and 2019 were used. Having children aged 0–4 years, having children aged 5–9 years, having children aged 10–14 years, having children aged 15–19 years, and the number of children were used as the indicators of child presence. The analysis was conducted by sex and marital status. We used a modified Poisson regression model to reveal the association between having children and smoking prevalence, and an ordinal logistic regression was used to investigate the association with the number of cigarettes smoked per day. Age group, household income, educational attainment, marital status, residential type, employment status, and year were used as other characteristics. RESULTS: Data from 18,261 people were analyzed. Having children aged 0–4 years was associated with lower smoking prevalence or fewer cigarettes smoked per day both in women and men, while no significant association was observed in unmarried women. In addition, having children aged 5–9 years, 10–14 years, or 15–19 years was not significantly associated with a lower smoking prevalence and fewer cigarettes smoked per day in women and men, whereas having children aged 5–9 years and having children aged 15–19 years were significantly associated with a higher smoking prevalence in married men. Moreover, a higher number of children was significantly associated with lower smoking prevalence in women, while having ≥ 3 children was significantly associated with higher smoking prevalence in married men. CONCLUSIONS: The associations of having children with smoking prevalence and intensity differed by child age, the number of children, parental sex, and marital status. Particularly, it was suggested that smoking cessation efforts are required among parents having children aged ≥ 5 years.