Characterization of Respiratory Systems Among Youth Using Heated Tobacco Products in Hong Kong

Importance Heated tobacco products (HTPs) are promoted as less harmful than combustible cigarettes but epidemiological evidence is scarce, especially in youth. Objective To investigate the associations of persistent respiratory symptoms with HTP use, cigarette use, and dual use among Hong Kong youth. Design, Setting, and Participants This was a territorywide cross-sectional school-based survey conducted from October 2018 to July 2019 using an anonymous questionnaire. Schools were randomly invited from a proportionate stratified sample in all 18 districts of Hong Kong. Poisson regression models using generalized estimating equations yielded adjusted prevalence ratios (APRs) of respiratory symptoms in (1) former and current HTP (vs never) users in the whole sample and stratified by cigarette use status and (2) exclusive HTP and dual users vs exclusive cigarette users. Statistical analysis was performed from October 2020 to March 2021. Exposures Former and current use of cigarettes, HTPs, e-cigarettes, and other tobacco products. Main Outcomes and Measures Respiratory symptoms for 3 consecutive months in the past 12 months

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

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.published_or_final_versionPublic HealthMasterMaster of Philosoph

Exposure to electronic cigarette advertising and intention to use electronic cigarettes in Hong Kong adolescents

Background Adolescent electronic cigarette (EC) use in relation to exposure to advertising has rarely been studied outside Western settings. We investigated the exposure to EC advertising in Hong Kong adolescents and its association with the intention to use ECs in never users. Methods In 2014/15, 40202 Secondary 1-6 (US grade 7-12) students (mean age 14.9, standard deviation 1.8; 51.5% boys) from 92 randomly selected schools completed an anonymous questionnaire. Exposure to messages directly or indirectly promoting ECs through each of 12 sources in the past 30 days, and the intention to use ECs in the next 12 months or when a good friend offered an EC were reported. Weighted prevalence of exposure to EC advertising was calculated. Logistic regression yielded adjusted odds ratios (AORs) of intention to use ECs for the exposure to EC advertising (versus no exposure to any source) in never EC users. Results In all students, 38.0% (95% confidence interval [CI] 37.5%-38.5%) were exposed to EC advertising, most commonly through television (15.1%). In never EC users (n=36274), any exposure to EC advertising was associated with an AOR (95% CI) of 1.50 (1.23-1.84) for the intention to use ECs, with increasing AORs for more sources of exposure (p for trend< 0.001) and an AOR of 2.20 (1.55-3.12) for 4 sources or more. Exposure through social networking sites (prevalence: 9.9%; AOR 2.58, 95% CI 2.03-3.27), video sites (4.4%; 2.56, 1.84-3.55) and other websites (2.5%; 2.26, 1.45-3.53) had the strongest associations with the intention to use ECs. Conclusions Four in 10 Hong Kong adolescents were exposed to EC advertising through different sources. The exposure was dose-dependently associated with an intention to use ECs in never users. Banning EC advertising may prevent EC use in adolescents

Cigarette and e-cigarette use in parents and their adolescents

Introduction Potential effects of parental e-cigarette use on adolescent tobacco use are understudied but have implications for tobacco and e-cigarette control. We investigated the associations of parental cigarette and e-cigarette use with adolescent use of these products. Methods A cross-sectional questionnaire survey was conducted in 26648 secondary school students (mean age 14.8 years, 54.7% boys) in Hong Kong in 2016/17. We examined the associations of paternal and maternal cigarette and e-cigarette use (study factors: abstinence [reference]/cigarette use only/dual use of cigarettes and e-cigarettes/e-cigarette use only) with cigarette and e-cigarette use stages (never, not susceptible [reference]/never, susceptible/ever, not current/current) in adolescents, with mutual adjustment of the study factors and adjustment of age, sex, and perceived family affluence. Results In general, parental cigarette use only, dual use, and e-cigarette use only (vs abstinence) were all associated with adolescent cigarette and e-cigarette use. The associations were generally strongest for parental e-cigarette use only, followed by dual use and cigarette use only. For example, the adjusted odds ratios (AORs) of adolescent current cigarette use were 43.03 (95% CI 23.85-77.63) for maternal e-cigarette use only, 10.90 (6.25-19.01) for dual use, and 3.13 (2.65-3.71) for cigarette use only; the corresponding AORs of adolescent current e-cigarette use were 71.37 (37.83-134.64), 17.29 (10.95-27.30), and 2.98 (2.44-3.64). Conclusions In Hong Kong adolescents, cigarette and e-cigarette use were generally more strongly associated with parental e-cigarette use than with parental cigarette use. These findings support the Government’s proposal to ban e-cigarettes to protect the health of young people

Prevalence and correlates of smoking at home in adolescent smokers - a cross-sectional study

Background Being able to smoke at home may facilitate adolescent smoking and nicotine dependence. However, this has rarely been studied. We studied the prevalence of smoking at home, its risk factors and potential effect on nicotine dependence in Hong Kong adolescent smokers. Methods In a cross-sectional school-based survey in 2014/15, 10932 secondary school students (mean age 14.8 years; 46.8% boys) indicated whether they smoked at home during 8 periods on weekdays and weekends, analysed as yes (any period) vs no. Also measured were urges to smoke (UTS, range 0-5, 5=greatest urge) based on the frequencies and strength of smoking urges; cigarettes smoked per day (CPD); past 30-day (current) smoking; and sociodemographic and other smoking-related characteristics. We investigated smoking at home's (1) risk factors and (2) associations with UTS and CPD (outcomes) in current smokers. Results Of 461 current smokers, 50.3% (95% CI 45.7-54.9) smoked at home, with “weekend mornings” being the most common (20.6%). Smoking at home was associated with having 2 or more co-residing smokers (vs none) and home thirdhand smoke exposure for 4-7 days/week (vs 0) with adjusted odds ratios of 1.38 (95% CI 1.09, 1.76) and 1.66 (1.23, 2.23). Smoking at home was also associated with UTS and CPD with adjusted β coefficients of 1.78 (1.17, 2.39) and 2.63 (1.27, 3.99). Conclusions About half the Hong Kong adolescent smokers smoked at home. Smoking at home was associated with living with smokers and a home environment with residual tobacco smoke, which probably make adolescent smoking difficult to detect. Smoking at home was also associated with higher nicotine dependence. Whether smoking cessation of family members and home smoking bans can reduce adolescent smoking at home and nicotine dependence should be further studied

Association of tobacco industry denormalisation beliefs with smoking cessation and nicotine addiction in adolescent smokers

Aim and objective To investigate the associations of tobacco industry denormalisation (TID) beliefs (ie, negative perceptions of the industry) with smoking cessation and nicotine addiction in adolescent smokers. Methods In 2012/13, a cross-sectional survey was conducted in 45857 secondary school students (mean age 14.8 years, 54% boys) in Hong Kong. TID beliefs (score range: 0-6) were measured by two questions: “Do you think the tobacco industry is respectable?” and “Do you think the tobacco industry tries to get youth to smoke?” Each question had 4 options (“probably yes” to “probably no”), which were assigned scores of 0-3, with larger scores indicating stronger TID beliefs. Also measured were smoking status, smoking cessation (yes/no; defined as cessation for ≥4 months), morning smoking (yes/no), cigarettes smoked per day, etc. Associations were examined with adjustment of sociodemographic characteristics, peer smoking, and numbers of co-residing smokers. Results In ever smokers (occasional or daily smoking either now or in the past; n=4544), TID beliefs were associated with an adjusted prevalence ratio (PR) of 1.04 (95% CI 1.02, 1.07; p=0.001) for smoking cessation. In past 30-day smokers (n=3250), TID beliefs were associated with an adjusted PR of 0.98 (0.96, 1.00; p=0.04) for morning smoking and an adjusted β of -0.27 (-0.44, -0.10; p=0.002) for cigarettes smoked per day. Conclusions In Hong Kong adolescents, TID beliefs were associated with smoking cessation in ever smokers, and inversely associated with nicotine addiction in past 30-day smokers. A TID component may strengthen cessation interventions in adolescent smokers. Funding Food and Health Bureau of the Hong Kong Government