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.