[Awareness of harm to others from secondhand smoke and smokers' interest in smoking cessation]

Objectives　Because smoking presents various health hazards, smoking cessation is important for health promotion. It is known that awareness of the harm of smoking to smokers themselves is associated with attempts to quit. However, the association between smoking cessation and awareness of harm to others from secondhand smoke has not been well examined. Therefore, in this research, we examined the association between smokers' awareness of the harm to others from secondhand smoke and their interest in smoking cessation, focusing on current smokers in an Internet survey of the general population of Japan.Methods　We conducted a cross-sectional Internet survey of the general population of Japan between January 27 and March 13, 2017. A total of 1,586 respondents aged 15-71 years (1,128 men and 458 women) who were current smokers were analyzed. We used multivariable-adjusted logistic regression to examine the association among awareness of smoking's harm to smokers themselves, awareness of harm to others from secondhand smoke, and the smokers' interest in smoking cessation.Results　Of current smokers, 81.6% of men and 88.2% of women were aware of the harm caused to others by secondhand smoke; 52.7% of men and 64.6% of women were interested in smoking cessation. Using awareness of harm to smokers themselves and awareness of harm to others from secondhand smoke as predictor variables in multivariable-adjusted logistic regression, odds ratios were 2.53 and 2.92, respectively. In the model using both awareness of harm to smokers themselves and harm to others from secondhand smoke, both have a significant independent positive association with smokers' interest in quitting.Conclusions　Current smokers aware of the harm caused to others by secondhand smoke were more interested in quitting than those who were not. Awareness of the harm caused to smokers themselves by smoking and awareness of the harm caused to others by secondhand smoke have a significant independent positive association with smokers' interest in quitting. Although this study is a cross-sectional study and did not investigate causal relationships, the findings suggest that raising awareness of the harm to other people from secondhand smoke may lead to more interest in smoking cessation, and the data can be used to promote tobacco control in the future.