Adolescent Tobacco Use Behavior and Nationwide School-Based Tobacco Control in Korea : A Multi-Year Study = 청소년의 담배 사용 행동과 한국의 학교 기반 담배규제

다국어 초록 (Multilingual Abstract)

Background
Adolescents spend a large part of their time in schools, where they form and reinforce their attitudes, beliefs, and social norms regarding health-related behaviors, including tobacco use. To combat the tobacco epidemic, the school environment has been targeted for interventions aimed at preventing and reducing tobacco use among adolescents. Since 2015, Korea has implemented comprehensive, nationwide school-based tobacco control programs. Over the past decade, various efforts have substantially reduced the prevalence of conventional cigarette use among adolescents. However, the recent emergence of novel tobacco products and the diversification of tobacco use behaviors pose new challenges to tobacco control. Furthermore, the coronavirus disease 2019 (COVID-19) pandemic led to school closures, presenting unprecedented educational challenges and complicating school-based tobacco control efforts, potentially impacting adolescent tobacco use behaviors. The Social Ecological Model (SEM) allows us to understand the multifaceted and interacting determinants of health behaviors. The school environment is both influenced by and influences various ecological systems. Therefore, understanding the multi-level influences is essential for developing and enhancing comprehensive tobacco control interventions for adolescents. This dissertation aims to explore changes in tobacco use behavior among Korean school adolescents over the past decade, including the period affected by COVID-19. Employing the SEM framework, the study aims to investigate multi-levels of influence affecting adolescent tobacco use behavior, with a particular focus on the perspective of school-based tobacco control.

Methods
In the first study, which aimed to identify developmental tobacco use trajectories from adolescence to young adulthood, six years of data (2011-2016) from the Korean Children and Youth Panel Survey were utilized, involving 1,723 school students. The study employed group-based trajectory modelling (GBTM) and multinomial logistic regression analysis to examine general individual, interpersonal, and school-level factors associated with different tobacco use trajectory groups. The second study examined the effects of individual and school-level factors, aligned with school-based tobacco control efforts, on adolescent tobacco use. This analysis used data from the 2015 School-Based Smoking Prevention Program Survey, which included 4,631 students nested within 62 secondary schools in Seoul, Korea. Multilevel logistic regression analyses were conducted to assess the influence of multi-level factors. Additionally, interaction analyses were performed to investigate whether gender moderates the impact of school programs and school-level norms, highlighting a cross-level interaction. In the third study, the impact of an environmental factor, such as school closures during the COVID-19 pandemic, on adolescents’ tobacco use behavior was examined, focusing on different types of tobacco products. This analysis drew on eight years of data (2015-2022) from the Korea Youth Risk Behavior Survey (KYRBS), encompassing 474,836 students. Interrupted time series (ITS) regression analyses were employed to examine changes in level and slopes of tobacco use before and after the onset of COVID-19. The study specifically investigated patterns of exclusive conventional cigarette (CC) use, exclusive electronic cigarette (EC) use, and polytobacco use before and after COVID-19, with a particular emphasis on gender differences. The final study aimed to examine the effects of individual experiences with school programs on quit attempts among adolescent tobacco users. For this purpose, logistic regression analyses were conducted using three years of data from KYRBS. The study further employed additive interaction analyses to examine whether the effects of school programs on tobacco quit attempts differed in the periods before and after the COVID-19 pandemic, highlighting a cross-level interaction.

Results
The first study identified four distinct developmental tobacco use trajectories from early adolescence to emerging young adulthood: never tobacco users (69.2%), persistent light tobacco users (8.7%), late escalators (10.3%), and early established tobacco users (11.9%). It also revealed that having peers who use tobacco significantly increases the risk of becoming either persistent light or early established tobacco users. Furthermore, less after-school supervision and attending a vocational high school were associated with an increased risk of becoming early established tobacco users. The second study demonstrated that school-based tobacco control programs and supportive school environments positively affect reducing adolescent tobacco use. Greater exposure to tobacco control programs and more negative school-level norms toward tobacco use were associated with a decreased risk of tobacco use. Conversely, the presence of tobacco using teachers and higher rates of tobacco use within school premises were associated with an increased risk. Furthermore, the effects of the programs and school-level norms on tobacco use was significantly moderated by gender., with boys more affected by the number of programs they participated in, and girls more influenced by the school-level norms. The third study highlights that the environmental changes, such as school closures during the COVID-19 pandemic, have either facilitated a transition from conventional cigarettes (CC) to electronic cigarette (EC), or led to increased polytobacco use among adolescents. After the pandemic, the prevalence of exclusive CC use significantly declined for both genders. Specifically, among girls, there was an overall decrease in the prevalence of exclusive CC use in 2020. In contrast, the use of any tobacco products or polytobacco products showed a significant increase in the post-pandemic linear trend for both boys and girls. Gender differences were observed. For exclusive EC use, a significant trend change was observed in 2020 for both genders. However, the increase in exclusive EC use during 2020 and its post-pandemic linear trend were significant only among girls, suggesting a gender-specific transition from CCs to ECs after the pandemic. The use of polytobacco products showed a significant increasing linear trend after the pandemic for both genders. However, the transition from CCs to ECs was more pronounced among girls, whereas polytobacco use increased more notably for boys. The fourth study demonstrated that individual experiences with school tobacco control programs increased the likelihood of quitting attempts among adolescent tobacco users, regardless of the type of tobacco products used. However, a negative interaction was observed between the COVID-19 period and experiences in school programs. This suggests that the effectiveness of school tobacco control programs in increasing quit attempts were diminished during the COVID-19 pandemic.

Conclusion
Utilizing the SEM framework, this dissertation investigated the multi-levels of influence, from individual to environmental factors, on adolescent tobacco use behavior. The study highlights that predictors identified in early adolescence persistently influence tobacco use into young adulthood, supporting the initiation of tobacco control interventions in early adolescence. Furthermore, this study highlights the positive effects of school-based tobacco control programs in reducing tobacco use and encouraging quit attempts among adolescent tobacco users. However, it noted that environmental changes during the COVID-19 pandemic have lessened the effectiveness of school-based tobacco control efforts. Consequently, there is an urgent need to reinstate resources to pre-pandemic levels to ensure the delivery of more effective interventions to students. Furthermore, the increasing use of novel tobacco products among adolescents calls for immediate action. Post-COVID-19, a notable gender-specific behavioral shift was observed, with girls transitioning from CC to EC, and boys exhibiting an increase in polytobacco use. These gender differences should be considered in future tobacco control strategies. Addressing tobacco use among adolescents is crucial for eradicating the tobacco epidemic and achieving a tobacco-free generation. Future initiatives should adopt a social ecological approach to combat the tobacco epidemic by considering all nicotine products as a whole, beyond just conventional cigarettes.

국문 초록 (Abstract)

배경
청소년들은 대부분의 시간을 학교에서 보내며, 학교라는 환경 안에서 담배 사용과 같은 건강 관련 행동에 대한 태도, 신념 및 사회적 규범을 형성하게 된다. 전 세계적으로 청소년의 담배 사용을 예방하고 감소시키기 위해 다양한 학교 기반의 흡연예방사업이 시행되었다. 한국은 2015년 담뱃값 인상 정책과 함께 흡연예방 정책을 강화하고 포괄적인 학교흡연예방사업을 전국으로 확대 시행하였다. 지난 10년 동안 학교흡연예방사업을 포함한 다양한 노력들이 학교 청소년의 일반담배 사용률을 감소시켰지만, 최근 청소년의 신종담배 사용 증가와 더욱 다양화된 담배 제품 사용 행태는 현 담배규제 정책에 새로운 과제를 안겨주고 있다. 또한 코로나19 팬데믹으로 인하여 학교 환경과 흡연예방사업 운영에도 많은 변화가 발생하여, 이 시기의 청소년 담배 사용 행태 변화를 탐색하는 연구가 필요하다. 사회생태학적 모델 (Social Ecological Model, SEM)은 건강 행동에 대한 다수준의 서로 상호작용하는 결정 요인들을 이해할 수 있도록 한다. 학교 환경은 다양한 생태학적 시스템에 영향을 미치고 또 영향을 받는다. 따라서 청소년을 위한 포괄적인 담배규제 정책을 강화하기 위해서는 사회생태학적 관점에서 다양한 영향 요인을 이해하는 것이 중요하다. 이에 본 연구는 코로나19 기간을 포함한 지난 10년 동안의 한국 학교 청소년들의 담배 사용 행동 변화를 탐색하고, 사회생태학적 모델을 활용하여, 청소년 담배 사용 행동에 영향을 미치는 다수준의 요인을 학교 담배규제 정책관점에서 탐색하고자 한다.
방법
첫 번째 연구에서는 청소년기부터 초기 청년기까지의 담배 사용 행태 변화를 확인하기 위해 2011-2016년 한국아동청소년패널조사에서 얻은 학생 1,723명의 종단자료를 사용하여 Group-based trajectory modeling (GBTM) 분석을 수행하였다. 또한 Multinomial logistic regression 분석을 통해 담배 사용 trajectory 그룹과 관련된 개인, 상호간, 및 학교 수준 요인을 탐색하였다.
두 번째 연구에서는 청소년의 담배 사용에 영향을 미치는 개인 및 학교 수준 요인을 탐색하기 위해, 2015년 학교흡연예방사업운영조사 자료에서 얻은 서울시 62개 중·고등학교 자료와 4,631명의 학생 데이터를 분석하였다. 또한 성별에 따라 학교 프로그램 참여 수준과 학교 수준 규범의 영향에 차이가 있는지 탐색하기 위해 상호작용 분석을 수행하였다.
세 번째 연구에서는 코로나19 팬데믹으로 인한 환경 변화가 청소년의 담배 사용 행태에 미치는 영향을 탐색하기 위해 2015-2022년 청소년건강 행태조사 자료에서 얻은 474,836명의 학생 데이터를 활용하여, Interrupted time series 회귀분석을 수행하였다. 이를 통해, 코로나19 전후 일반담배, 액상형/궐련형 전자담배 및 다중 담배 사용 패턴 변화를 비교하였다.
네 번째 연구에서는 개인의 학교 흡연예방 및 금연프로그램 참여 경험이 흡연자의 금연 시도에 미치는 영향을 탐색하기 위해, 청소년건강행태조사의 3개년 자료를 분석하였다. 로지스틱 회귀분석 및 상호작용 분석을 통해, 코로나19 전후로 학교 프로그램의 영향 차이가 있는지 탐색하였다.
결과
첫 번째 연구 결과, 초기 청소년기부터 청년기까지 총 4개의 담배 사용 trajectory 그룹을 확인하였다. 이 연구에서 초기 청소년기에 방과 후 보호자 부재 일수가 많은 학생은 early established 흡연자가 될 위험이 높았으며, 흡연 친구는 persistent light 흡연자 또는 early established 흡연자가 될 위험을 증가시켰다. 학교 수준에서는 특성화 고등학교에 다니는 학생들이 early established 흡연자가 될 가능성이 높은 것으로 나타났다.
두 번째 연구 결과, 더 많은 학교 프로그램에 노출되고, 담배 관련 규범 수준이 높은 학교의 학생일수록 흡연 위험이 감소하는 것으로 나타났다. 반면, 학교 내 흡연 교사 목격 경험과 학교 수준의 높은 흡연율은 학생 개인의 흡연 위험을 증가시켰다. 또한 프로그램 참여 정도에 따른 효과는 성별에 따라 차이를 보였다. 남학생은 개인의 참여 수준에 영향을 많이 받는 것으로
나타났고, 여학생은 학교 수준의 규범과 같은 환경의 영향을 더 많이 받는 것으로 나타났다.
세 번째 연구는 코로나19 팬데믹으로 인한 환경 변화가 일반담배에서 액상형 전자담배나 궐련형 전자담배 사용으로의 전환, 또는 다중 담배 사용을 촉진했을 가능성을 제시하였다. 2020년 코로나19 이후 청소년의 일반담배 사용률이 감소한 반면, 남학생 사이에서는 코로나19 이후 다중 담배 사용은 증가하는 패턴을 보였다. 또한 여학생은 코로나19 이후 다중 담배 사용뿐만 아니라, 액상형 전자담배 단독 사용이 급격하게 증가하여, 포스트 코로나 시기에 일반담배에서 엑상형 전자담배로 제품 사용이 변화하였음을 확인하였다.
네 번째 연구 결과, 학교 흡연예방 및 금연 프로그램에 대한 개인의 경험이 금연 시도를 증가시키는 것으로 나타났다. 또한 코로나19 전후로 금연 시도에 대한 효과 차이를 분석한 결과, 코로나19 이후에는 교육의 영향이 감소한 것으로 나타났다.
결론
본 연구는 사회생태학적 모델을 적용하여 청소년 담배 사용 행태에 영향을 미치는 다수준의 영향요인을 탐색하였다. 본 연구는 학교 기반 담배규제 정책 사업이 청소년의 담배 사용 감소 및 금연 시도 증가에 긍정적인 효과가 있음을 확인하였으며, 사업이 축소된 코로나19 시기에 그 효과가 감소한 것을 확인하였다. 따라서 청소년들에게 효과적인 프로그램을 제공하기 위해, 코로나19로 축소된 사업을 이전 수준으로 회복시켜야 할 것으로 보인다. 더욱이 청소년의 신종담배 사용률이 증가하고, 성별 간 담배 사용 행동 변화에 차이를 보임에 따라, 향후 청소년 담배규제 정책은 이러한 점들을 고려해야 할 것이다. 청소년은 담배없는 세대 실현의 주역이다. 청소년 담배규제 정책은 생태학적 접근을 통해 발전시켜야 하며, 일반담배뿐만 아니라 신종담배 전체를 고려하여 중재 전략을 세워야 할 것으로 보인다.

목차 (Table of Contents)

• Abstract ⅰ
• Contents ⅶ
• List of Tables ⅸ
• List of Figures xi
• Chapter 1. Introduction 1
• 1.1 Changes in adolescent tobacco use 2
• 1.2 Efforts to prevent adolescent tobacco use: school-based approach 6
• 1.2.1 School-based tobacco control in Korea 9
• 1.2.2 School closure and school tobacco control during COVID-19 12
• 1.3 Study framework 14
• 1.3.1 Social ecological model (SEM) 14
• 1.3.2 Study questions and modified SEM 16
• 1.4 Study objectives 19
• Chapter 2. Developmental trajectories of tobacco use in adolescence, 2011-2016 22
• 2.1 Introduction 23
• 2.2 Methods 25
• 2.3 Results 31
• 2.4 Discussion 37
• 2.5 Appendix 42
• Chapter 3. School-based tobacco control and adolescent tobacco use in 2015 46
• 3.1 Introduction 47
• 3.2 Methods 51
• 3.3 Results 56
• 3.4 Discussion 66
• 3.5 Appendix 71
• Chapter 4. Changes in adolescent tobacco product use behavior after school closures during COVID-19 73
• 4.1 Introduction 74
• 4.2 Methods 77
• 4.3 Results 81
• 4.4 Discussion 94
• 4.5 Appendix 98
• Chapter 5. Changes in impact of school-based tobacco control programs on adolescents’ quitting attempts after COVID-19 100
• 5.1 Introduction 101
• 5.2 Methods 103
• 5.3 Results 107
• 5.4 Discussion 113
• 5.5 Appendix 116
• Chapter 6. Overall discussion 117
• 6.1 Summary 118
• 6.2 Interpretation in social ecological perspective 121
• 6.3 Implications 125
• 6.4 Limitations and recommendations 129
• 6.5 Conclusion 133
• References 135
• Abstract in Korea 149

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