Schroeder Institute at Truth Initiative, Washington, DC.
Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
Nicotine Tob Res. 2019 Mar 30;21(4):458-468. doi: 10.1093/ntr/ntx285.
Among youth, the frequency and prevalence of using more than one tobacco (small cigar, cigarette, and hookah) or nicotine-containing product (e-cigarettes-ENDS) are changing. These shifts pose challenges for regulation, intervention, and prevention campaigns because of scant longitudinal data on the stability of use patterns in this changing product landscape.
A nationally representative longitudinal survey of 15- to 21-year olds (n = 15,275) was used to describe transitions between never use, noncurrent use, and past 30-day use of combustible tobacco, e-cigarettes (ENDS), and dual use of both kinds of products. A multistate model was fit to observations collected every 6 months across 2.5 years to estimate the probability of transitions between states (TPs), the average time in state (sojourn time), and the effect of age on transitions.
Current state strongly predicted future state over time intervals of 1 year or less, but only weakly predicted future state at longer intervals: TP to noncurrent use was higher for ENDS-only than combustible-only users over a 6-month interval but was similar for both groups over a 2-year interval. Sojourn time was significantly longer for combustible-only (0.52 years) and dual use (0.55 years) than ENDS-only use (0.27 years); older youth were more likely than younger youth to stay combustible tobacco users or noncurrent users.
The dynamics of transitions between combustible tobacco products and ENDS in a population of youth and young adults suggest that policy and prevention efforts must consider the frequent changes and instability over a 1-year or less time period in use patterns among young people.
The study addresses an urgent need in public health for timely information on how youth and young adults use tobacco and nicotine products. We found that youth, particularly adolescents, moved frequently between using ENDS and combustible tobacco products either alone or together. Importantly, the utility of current-use states for predicting future use states declined for time horizons longer than 1 year. Our results demonstrate a need for caution in interpreting product transitions. Longitudinal data with frequent observations and coverage of a wide range of possible product types is required to fully characterize usage patterns in youth.
在年轻人中，使用一种以上烟草（小雪茄、香烟和水烟）或含尼古丁产品（电子烟-ENDS）的频率和流行率正在发生变化。由于关于这种不断变化的产品格局中使用模式稳定性的纵向数据很少，这些变化给监管、干预和预防活动带来了挑战。
使用全国代表性的 15 至 21 岁青年（n=15275）纵向调查来描述从不使用、非当前使用和过去 30 天使用可燃烟草、电子烟（ENDS）以及同时使用这两种产品之间的转变。使用多状态模型对 2.5 年内每 6 个月收集的观察结果进行拟合，以估计状态之间转变的概率（TP）、状态停留时间（居留时间）以及年龄对转变的影响。
当前状态在 1 年或更短的时间间隔内强烈预测未来状态，但在较长时间间隔内预测未来状态的能力较弱：在 6 个月的间隔内，ENDS 仅使用者向非当前使用者的转变概率高于可燃烟草仅使用者，但在 2 年的间隔内，两者相似。可燃烟草仅使用者（0.52 年）和双重使用者（0.55 年）的居留时间明显长于 ENDS 仅使用者（0.27 年）；年龄较大的青少年比年龄较小的青少年更有可能保持可燃烟草使用者或非当前使用者。
在年轻人中，可燃烟草产品和 ENDS 之间的转变动态表明，政策和预防工作必须考虑在 1 年或更短的时间内年轻人使用模式的频繁变化和不稳定。
本研究满足了公共卫生领域对了解年轻人使用烟草和尼古丁产品方式的及时信息的迫切需求。我们发现，年轻人，尤其是青少年，经常在单独或同时使用 ENDS 和可燃烟草产品之间转换。重要的是，对于超过 1 年的时间范围，当前使用状态预测未来使用状态的效用下降。我们的研究结果表明，在解释产品转变时需要谨慎。需要具有频繁观察和广泛产品类型覆盖的纵向数据来充分描述年轻人的使用模式。
