[Awareness of secondhand smoke hazards and its influencing factors among Chinese adults in 2018].

[OBJECTIVE] To assess the awareness of tobacco-related health hazards and its associated factors among adults aged ≥18 years in China.

[METHODS] Data were derived from the 2018 China Chronic Disease and Risk Factor Surveillance, a nationally representative survey using a multistage stratified cluster sampling design. Awareness rates and 95%CI were estimated using complex sampling weights. Factors associated with awareness of SHS hazards were analyzed using weighted multivariable logistic regression.

[RESULTS] In 2018, the proportions of Chinese adults aged ≥18 years who were aware that exposure to secondhand smoke could cause adult lung cancer, childhood lung diseases, and adult heart disease were 69.81%, 66.83%, and 52.88%, respectively. The awareness rate that secondhand smoke can cause at least one disease was 72.61%. Univariate analyses showed that awareness of secondhand smoke-related health hazards differed significantly across subgroups defined by age, marital status, household annual income, urban-rural residence, geographic region, educational attainment, and smoking status(P<0.001). Multivariable logistic regression showed that age ≥65 years(OR =0.41, 95%CI 0.37-0.44), being unmarried(OR=0.76, 95%CI 0.70-0.83), low income(OR=0.66, 95%CI 0.62-0.71), rural residence(OR=0.68, 95%CI 0.65-0.71), residence in western regions(OR=0.64, 95%CI 0.61-0.67), low educational attainment(OR=0.09, 95%CI 0.08-0.11), and current smoking(OR=0.85, 95%CI 0.81-0.89) were independently associated with a lower awareness that secondhand smoke causes at least one disease(P<0.01). Awareness levels varied substantially across provinces, with higher awareness observed in Beijing and Shanghai(≥80% for adult lung cancer and childhood respiratory diseases, and ≥70% for heart disease), whereas awareness remained low in provinces such as Guizhou and Tibet, particularly for heart disease(<50%).

[CONCLUSION] In 2018, awareness of the health hazards of secondhand smoke among Chinese adults aged ≥18 years remained relatively low, particularly regarding adult heart disease. Awareness rates varied across population groups and provinces, with lower levels observed among individuals aged ≥65 years, single, low-income, rural, western-region residents, those with lower education, and smokers; provincially, Guizhou and Tibet showed relatively low awareness.