Prevalence, frequency, intensity, and location of cigarette use among adolescents in China from 2013-14 to 2019: Findings from two repeated cross-sectional studies.

Background: The burden of disease caused by tobacco use is a grave public health concern in China. Preventing smoking initiation among adolescents will lower the prevalence of adult tobacco use later. Surveillance of tobacco use among adolescents helps set priorities in developing tobacco control policies. We aim to ascertain the prevalence and differences of cigarette use across sex, grade, and region among middle and high school students in 2019 and associated changes from 2013-14 to 2019 among middle school students. Methods: Using a multistage stratified cluster-randomized sampling design with national and provincial representativeness, we conducted two school-based cross-sectional surveys in 2013-14 and in 2019. A total of 155 117 middle school students in grades 7-9 in 2013-14 and 288 192 middle and high school students in grades 7-12 in 2019 were interviewed. Self-reported experimental and current (past 30-day) cigarette use among middle school and high school students; frequent use (≥20 days in the past 30 days) and intensity (>20 cigarettes per day) of smoking among current cigarette users; and location of smoking among current cigarette users were investigated. All estimates were weighted based on the complex sampling design. Findings: The 2013-14 survey (overall response rate: 98.1%) included 155 117 middle school students (47.1% girl). The 2019 survey (overall response rate: 98.7%) included 147 270 middle school students (46.5% girl), 106 432 academic high school students (50.8% girl) and 34 490 vocational high school students (43.8% girl). In 2019, the prevalence rate of experimental and current cigarette use was 12.9% and 3.9% for middle school students, 21.6% and 5.6% for academic high school students, and 30.3% and 14.7% for vocational high school students, respectively, with large sex and regional differences. The prevalences of smoking on 20 or more days and daily cigarette use in the past 30 days were higher in vocational high school (5.9%, 4.1%) than in academic high school (1.8%, 1.2%) and middle school (0.7%, 0.5%), and higher among boys than girls. The proportions of current cigarette users smoking more than 20 cigarettes per day in the past 30 days for girls were higher than for boys in academic high school. Students usually smoke at school and at home. Boys were more likely to use cigarettes in an internet cafe, while girls often smoked at social venues. From 2013-14 to 2019, the prevalences of experimental and current cigarette use declined by 5.0% and 2.0% (percentage points), respectively, among middle school students but increased by 1.4% and 0.5% (percentage points) among rural girls. Among current cigarette users in middle school students, the proportions of heavy cigarette use (>20 cigarettes per day) have increased by 1.8 percentage points, mainly among boys, by 2.2% (percentage points). Interpretation: From 2013-14 to 2019, the prevalences of experimental and current cigarette use among middle school students decreased overall but increased among rural girls, while the intensity of cigarette use rose among boys. Cigarette use among Chinese adolescents differs across sex and regions, with higher rates among boys, in rural areas, and in the Western region (low socioeconomic status). Smoking is much more prevalent in vocational high schools than the other settings. Effective targeted tobacco control interventions among adolescents are urgently needed in China. Funding: Dr. Zhuo Chen is supported by National Natural Science Foundation (Grant#: 72174098) through the University of Nottingham Ningbo China.