Territory-wide study on smoking exposure in adolescents and children

Abstract

Introduction: Decades of progressive tobacco control measures have seen adult smoking rates in Hong Kong reduced to among the lowest in the world. Comprehensive smokefree policies have also reduced secondhand smoke (SHS) exposure in public places and indoor workplaces. However, children remain unprotected from SHS in the family home and in non-smokefree public places. This presentation summaries the trends, risk factors and harms of cigarette smoking and SHS exposure in Hong Kong adolescents and children. Methods: Data were collected through territory-wide school-based surveys of primary and secondary school students in the past 2 decades. Primary school data were mainly based on surveys conducted for the Hong Kong Council on Smoking and Health (COSH). More recent surveys were also commissioned by the Food and Health Bureau (FHB). Secondary school data were from smoking surveys funded by COSH, Department of Health and FHB, and other health surveys. The prevalence of smoking and SHS exposure were calculated. Multivariate analyses were conducted to investigate risk factors and harms. Results: The prevalence of current smoking (past 30 days) has been reducing, reaching 0.3% in Primary 4 to 6 students and 3.3% in Secondary 1 to 6 students in 2012-13. However, the prevalence of SHS exposure at home in the past 7 days remained high in Primary 4-6 (24.5%) and Secondary 1-6 (23.2%) students in 2012-13. SHS exposure at home from neighbours was also reported. Comprehensive smokefree policies in 2007 might have displaced some smoking into the homes of young children. Overestimation of peer smoking predicted smoking initiation. Family smoking and SHS exposure at home predicted smoking initiation, nicotine addiction and lower likelihood of quitting. Risk factors of smoking also included peer smoking, non-intact family structure, non-authoritative maternal parenting, and parental pro-smoking practices. Smoking was associated with respiratory symptoms, sleep problems, depressive symptoms and poor self-rated health. SHS exposure was associated with respiratory symptoms and health services use in current smokers, poor school performance in never smokers, and family unhappiness. Preliminary evidence showed that simple school- and family-based interventions was effective in reducing SHS exposure in primary school students. Conclusions: While cigarette smoking in Hong Kong children and adolescents has reduced to low levels, exposure to SHS at home remain unacceptably high. Policies protecting young people from SHS at home and other places are needed. Locally relevant risk factors and potential harms of smoking were identified and these results can be used in tobacco control interventions for children and parents.