Preventing and reducing tobacco use in children and adolescents in Hong Kong

Abstract

Although the prevalence of tobacco use in Hong Kong is low, children and adolescents may still be susceptible to tobacco use. I investigated the personal and environmental risk factors of tobacco use and evaluated the effects of a drama intervention, pictorial warnings on cigarette packets, and parental involvement in preventing and reducing tobacco use in children and adolescents.

This thesis comprises 3 studies. The first study was a drama intervention on tobacco industry denormalisation, which recruited 5497 Primary 2-4 students from 30 randomly selected schools in 2018-19. Their 1) knowledge of nicotine, thirdhand smoke, and electronic cigarettes, 2) attitudes towards the tobacco industry, 3) susceptibility to tobacco use, 4) intention to encourage smoking parents to quit, and 5) sociodemographics were assessed. The second study was a cross-sectional study that recruited 26648 Secondary 1-6 students from 83 randomly selected schools in 2016/17. They provided information on 1) parental comments on tobacco-related issues, 2) family and others’ awareness of their tobacco use behaviours, 3) parental intervention in their tobacco use behaviours, and 4) sociodemographics. The third study was a focus group study that explored the perceptions of 35 Primary 4 to Secondary 3 students towards 4 types of cigarette packets (with 50% pictorial health warnings, with 85% pictorial health warnings, drab brown plain packets, and lime green plain packets) in 2017. Chi-square tests, Fisher’s exact tests, McNemar’s tests, and Poisson regressions were used to analyse categorical dependent variables. T-tests and one-way ANOVA were used to analyse continuous dependent variables, whereas Mann-Whitney U tests and Kruskal-Wallis tests were used for continuous dependent variables that were not normally distributed.

One in 7 (14.1%) Primary 2-4 children were susceptible to tobacco use and 37.3% had a positive attitude towards the tobacco industry, particularly those who were living with tobacco users. The drama intervention improved their tobacco-related cognitions and increased their intention to encourage parental smoking cessation, particularly in students who had never used tobacco. Cigarette packets with 50% branding elements were still perceived as attractive to the students. Enlarging pictorial warnings from 50% to 85% and plain packets reduced perceived attractiveness, increased perceived harmfulness, addictiveness, and effectiveness in deterring smoking. Among adolescents, pro-cigarette parental comments were associated with a higher susceptibility to smoke, whereas anti-tobacco parental comments were associated with less positive attitudes towards tobacco use, but not tobacco cessation. Only around half (56.1%) of the adolescent ever tobacco users were identified by parents, of whom around one-third of parents did not intervene. Nevertheless, adolescents who were intervened by parents reported lower consumption level of cigarettes and more quit attempts. Current tobacco use was most commonly known by friends or classmates (68.2%), followed by family members (67.2%), school staff (20.2%), others (9.8%) and health professionals (4.2%).