Thirdhand smoke beliefs and behaviors among families of primary school children in Shanghai.

Introduction: There are few reports on the beliefs about thirdhand smoke in Chinese families with primary school children. This study aims to understand the beliefs about thirdhand smoke among parents or grandparents of primary school children in Shanghai and to provide an evidence base to incorporate thirdhand smoke preventative action into tobacco control interventions.

Methods: We performed a cross-sectional survey among parents and grandparents of children aged 6-13 years in the Changjiang Road Primary School and recruited 843 participants to make assessments on the 'beliefs about thirdhand smoke' (BATHS) scale. Sociodemographic details including age, gender, marital status, education level, personal income and type of home ownership (new house, secondhand house with or without redecoration) and health status of children (whether they suffered from respiratory diseases or not) were investigated. Scale assessment, univariate and multivariate analyses to explore the factors influencing the BATHS scale and subscale scores, were performed using SPSS version 22.0.

Results: Participants who were aged >65 years were more likely to get lower scores on the BATHS scale (OR=0.476; 95% CI: 0.311-0.728, p=0.001). Undergraduates (OR=1.190; 95% CI: 1.020-1.388, p=0.027) and graduates (OR=1.4490; 95% CI: 1.102-1.906, p=0.008) obtained higher scores. Moreover, the scores of residents living in a secondhand house with redecoration (OR=0.882; 95% CI: 0.782-0.995, p=0.041) and without redecoration (OR=0.801; 95% CI: 0.698-0.919, p=0.002) were lower compared with those of new-house owners. The scores for participants whose children suffered from respiratory diseases in the past six months (OR=1.104; 95% CI: 1.003-1.216, p=0.043) were higher than those whose children had no respiratory diseases.

Conclusions: This study shows that younger people, females, those with higher incomes, and higher education levels, were more likely to believe the thirdhand smoke impacts on health and its persistence in the environment. Our findings can guide targeted actions for smoke-free home interventions.