Sex and macroeconomic differences and trends in early attempts at cigarette smoking among adolescents: findings from 147 countries.

BACKGROUND: Most tobacco users initiate smoking during adolescence. Little is known about the global prevalence and trends in early cigarette smoking among adolescents. This study aimed to evaluate the prevalence of early attempts at cigarette smoking and its change trends among young adolescents. METHODS: We used data from the Global Youth Tobacco Surveys on adolescents aged 12-16 years, comprising 456,634 participants from 147 countries between 2006 and 2018, to estimate the prevalence of early attempts at cigarette smoking and age distribution at attempt by sex, country income, purchasing power parity (PPP) per capita, and WHO region. We assessed the average annual rate of reduction (AARR) in the prevalence of attempts at cigarette smoking before 12 years of age in 70 countries that had data from three or more surveys completed between 1999 and 2018. RESULTS: The average prevalence of early attempts at cigarette smoking was 12.2% (95% CI: 10.9-13.5) for boys and 6.7% (95% CI: 5.8-7.6) for girls, with the highest prevalence of 17.4% for boys and 10.7% for girls in the European region. Along with the growth of the national economy, the prevalence of early attempts at cigarette smoking gradually increased in both sexes. A total of 22.9% and 30% of countries had a negative change in AARR for boys and for girls, respectively. The countries with an upward prevalence were mainly located in the Eastern Mediterranean, Southeast Asia, and African regions. The age distribution at first cigarette smoked did not differ substantially between sexes. Notably, the age at first cigarette smoked of 10.7 years for girls was significantly earlier than that of 11.8 years for boys in low-income countries. Among cigarette-smoking adolescents, the average percentage of girls reporting smoking their first cigarette at an age <12 years was 55.7% in Q1 for PPP quintiles, 46.5% in Q2, 40.3% in Q3, 38.4% in Q4, and 34.6% in Q5, and the corresponding prevalence for boys was 46.0% in Q1, 42.8% in Q2, 42.9% in Q3, 43.5% in Q4, and 41.1% in Q5. CONCLUSIONS: The global prevalence of early attempts at cigarette smoking among adolescents was substantial, with differences by sex and macroeconomic situation, and our findings stress that interventions and policies targeting the first smoking experience are required to prevent the initiation of tobacco use among early adolescents, especially girls in low-income countries.

Physical Activity and Sedentary Behavior among Young Adolescents in 68 LMICs, and Their Relationships with National Economic Development.

It is unclear whether physical activity and sedentary behavior are associated with economic development in low- and middle-income countries (LMICs). We aimed to assess the association between these two behaviors and country economic development among young adolescents in LMICs. Data came from the Global School-based Student Health Survey (GSHS) conducted between 2009 and 2016 in 68 LMICs. A total of 180,298 adolescents aged 12-15 years were included; 15.3% of young adolescents achieved the recommended level for sufficient physical activity (≥60 min/day of physical activity of any kind per week according to WHO) and 64.6% achieved a low sedentary behavior (≤2 h of sitting activities/day according to some guidelines, not accounting for sitting time at school or for doing homework). However, only 9.1% of young adolescents met the recommended levels of both behaviors. Comparing the lowest to the highest quintiles of a country's purchasing power parity per capita (PPP), mean values of both physical activity (boys: 2.55 to 2.96 days/week; girls: 2.10 to 2.31 days/week) and sedentary behavior(boys: 1.86 to 3.13 h/day; girls: 1.83 to 3.53 h/day) increased. The prevalence of having both recommended behaviors decreased among boys (12.0% to 10.0%) and girls (9.6% to 4.9%) (p < 0.001). Although there might be an ecological fallacy, the findings emphasize the need for interventions to increase physical activity and reduce sedentary behavior among children and young adolescents.