BACKGROUND: Secondhand smoke (SHS) constitutes a significant health risk for the nearly half of children worldwide who are exposed to it. Could increasing knowledge about the harms of SHS to children lead smokers to quit? This study is the first to examine whether knowledge of SHS harms to children is related to intentions to quit among adults who smoke in Japan.
METHODS: Data came from the 2021 (Wave 4) ITC Japan Survey, a prospective cohort survey of a nationally representative sample of Japanese adults who smoke cigarettes (n=2586). Weighted logistic regression accounting for sampling design was used to analyse the association between respondents’ knowledge of child health (whether smoking causes harm and asthma in children), concern about setting an example for children (whether respondents worried that their cigarette smoking would influence children around them and whether they thought about quitting because they wanted to set an example for children), and their intention to quit.
RESULTS: 70.1% of respondents believed that SHS caused harm to children’s health, while 64.5% believed that SHS caused children’s asthma. Those who were more knowledgeable about the harms caused by SHS to children were significantly more likely to have intentions to quit (ꞵ=0.30, p=0.002). The results did not differ based on whether or not they had children. Those who believed their smoking behaviour influenced children to smoke cigarettes were much more likely to have intentions to quit (ꞵ=1.03, p<0.001), and for those who had children the relationship was even stronger (interaction ꞵ=0.31, p=0.046).
CONCLUSIONS: Concerns about the influence of smoking to children were significantly related to quit intentions, suggesting that interventions to increase awareness among adults who smoke may reduce children’s exposure through increased quitting, especially among those with children.