Family smoking, exposure to secondhand smoke at home and family unhappiness in children and adolescents

Abstract

Tobacco use adversely affects many aspects of well-being and is generally disliked by non-smokers. It is therefore possible for smoking in family members and secondhand smoke (SHS) exposure at home to affect family happiness. However, I found only one qualitative study and no epidemiological study on this topic. This thesis aimed to investigate the cross-sectional associations of family smoking and SHS exposure at home with family unhappiness in children and adolescents in Hong Kong.

Two cross-sectional school-based surveys were respectively conducted in primary and secondary students in Hong Kong. The primary student survey included 1239 students (mean age 8.5 years, standard deviation 0.9; 42.6% boys) from 7 schools, and the secondary student survey included 45857 students (14.8, 1.9; 54.0%) from 75 schools. In both surveys, students reported the number of co-residing smokers (family smoking), SHS exposure at home and whether their families had any unpleasant experience caused by smoking or SHS (tobacco-related unpleasant experience) and rated the overall level of happiness of their families (family unhappiness).

I conducted analysis in the primary and secondary students separately using multivariable logistic regression. I studied (i) the associations of tobacco-related unpleasant experience and family unhappiness (outcomes variables) with family smoking in the whole sample and in those without SHS at home and (ii) the associations of the outcome variables with SHS at home in those with family smoking. I also conducted a series of sensitivity analyses respectively using multi-nominal logistic regression, multiple imputation and coarsened exact matching.

Family smoking, SHS at home, tobacco-related unpleasant experience and family unhappiness were reported by 40.7%, 24.1%, 27.5% and 16.6% of primary students, respectively. The corresponding proportions in secondary students were 41.1%, 24.5%, 37.1% and 13.5%.

For tobacco-related unpleasant experience in the primary students, the adjusted odds ratio (AOR) related to family smoking in those without SHS at home (AOR 4.75, 95% confidence interval 3.97-5.67) was higher than the AOR related to SHS at home in those with family smoking (1.45, 0.99-2.13). In the secondary students, the corresponding AORs (95% confidence interval) were 5.25 (4.77-5.77) and 2.74 (2.56-2.94).

For family unhappiness in the primary students, the AORs related to family smoking in the whole sample and in those without SHS at home were 2.86 (1.90-4.31) and 2.28 (1.51-3.44), and the AOR related to SHS at home in those with family smoking was 1.83 (1.33-2.50). In the secondary students, the corresponding AORs were 2.00 (1.85-2.17), 1.34 (1.23-1.45) and 1.63 (1.51-1.75). The sensitivity analyses did not yield meaningfully different results.

In conclusion, family smoking, SHS exposure at home and tobacco-related unpleasant experience were prevalent in Hong Kong families. Family unhappiness was associated with both family smoking and SHS exposure at home in both children and adolescents. Tobacco use may adversely affect family happiness. Such impact of tobacco use, if confirmed in future research, adds to the justification for more stringent tobacco control measures and should be communicated to the public to encourage banning smoking at home and smoking cessation.