School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
Behavioral Sciences Group, Sanford Research, Sioux Falls, SD, USA.
Addiction. 2020 Dec;115(12):2369-2378. doi: 10.1111/add.15099. Epub 2020 May 19.
Recent nicotine use trends raise concerns that electronic cigarettes (ECs) may act as a gateway to cigarettes among adolescents. The aims of this study were to examine prevalence trends of exclusive EC use, exclusive cigarette use and dual use to determine the corresponding ages of initiation and to investigate hypothetical trends in total nicotine use and cigarette use in the absence of ECs among US adolescents.
Observational study using data from the National Youth Tobacco Survey (NYTS) to statistically model trends in the prevalences of each user group and their initiation ages. Projections from counterfactual models based on data from 1999 to 2009 (before EC introduction) were compared with actual trends based on data from 1999 to 2018. Rigorous error analyses were applied, including Theil proportions.
USA.
Adolescents aged 12-17 years who were established exclusive cigarette users (≥ 100 cigarettes smoked and ≤ 100 days vaped), established exclusive EC users (< 100 cigarettes smoked and > 100 days vaped) and established dual users (≥ 100 cigarettes smoked and > 100 days vaped), based on cumulative life-time exposure (n ≈ 12 500-31 000 per wave).
Exclusive cigarette use prevalence declined from 1999 to 2018, while exclusive EC use and dual use prevalences increased since their introduction in 2009. The age of cigarette initiation began a slight increase after 2014, whereas the age for EC use remained approximately constant and was higher than that of cigarettes. The counterfactual comparison results were consistent with ECs not increasing the number of US adolescent nicotine users, and in fact diverting adolescents from cigarettes.
Electronic cigarettes may have offset conventional smoking among US adolescents between 2010 and 2018 by maintaining the total nicotine use prevalence and diverting them from more harmful conventional smoking. Additionally, electronic cigarette users appear to initiate at older ages relative to conventional smokers, which is associated with lower risk.
最近尼古丁使用趋势令人担忧，电子烟（EC）可能成为青少年吸烟的入门途径。本研究旨在检查独家 EC 使用、独家香烟使用和双重使用的流行趋势，以确定相应的起始年龄，并调查如果没有 EC，美国青少年的总尼古丁使用和香烟使用的假设趋势。
利用全国青少年烟草调查（NYTS）的数据进行观察性研究，对每个用户群体的流行趋势及其起始年龄进行统计建模。基于 1999 年至 2009 年（EC 引入前）的数据的反事实模型的预测与基于 1999 年至 2018 年的数据的实际趋势进行了比较。应用了严格的误差分析，包括泰尔比例。
美国。
根据终生累计暴露量（每波约 12500-31000 人），被确定为已建立的独家香烟使用者（≥100 支香烟吸烟且≤100 天蒸气吸入）、已建立的独家 EC 用户（<100 支香烟吸烟且>100 天蒸气吸入）和已建立的双重使用者（≥100 支香烟吸烟且>100 天蒸气吸入）的 12-17 岁青少年。
自 2009 年 EC 推出以来，独家香烟使用的流行率从 1999 年下降，而独家 EC 使用和双重使用的流行率则有所增加。自 2014 年以来，香烟的起始年龄略有上升，而 EC 使用的年龄保持不变，且高于香烟。反事实比较结果与 EC 不增加美国青少年尼古丁使用者数量的情况一致，事实上，EC 使青少年远离了更有害的传统吸烟。
2010 年至 2018 年，电子烟可能通过维持总尼古丁使用流行率并使青少年远离危害更大的传统吸烟，从而抵消了美国青少年的常规吸烟。此外，与传统吸烟者相比，电子烟使用者似乎开始吸烟的年龄更大，这与风险较低有关。
