Department of Population Health, University of North Dakota, Grand Forks, ND.
Psychology Department, Wesleyan University, Middletown, CT.
Nicotine Tob Res. 2018 Sep 4;20(10):1272-1277. doi: 10.1093/ntr/ntx160.
E-cigarettes (Electronic Nicotine Delivery Systems, or ENDS) are an increasingly popular tobacco product among youth. Some evidence suggests that e-cigarettes may be effective for harm reduction and smoking cessation, although these claims remain controversial. Little is known about how nicotine dependence may contribute to e-cigarettes' effectiveness in reducing or quitting conventional smoking.
A cohort of young adults were surveyed over 4 years (approximately ages 19-23). Varying-coefficient models (VCMs) were used to examine the relationship between e-cigarette use and conventional smoking frequency, and how this relationship varies across users with different nicotine dependence levels.
Lifetime, but not recent, e-cigarette use was associated with less frequent concurrent smoking of conventional cigarettes among those with high levels of nicotine dependence. However, nondependent e-cigarette users smoked conventional cigarettes slightly more frequently than those who had never used e-cigarettes. Nearly half of ever e-cigarette users reported using them to quit smoking at the last measurement wave. For those who used e-cigarettes in a cessation attempt, the frequency of e-cigarette use was not associated with reductions in future conventional smoking frequency.
These findings offer possible support that e-cigarettes may act as a smoking reduction method among highly nicotine-dependent young adult cigarette smokers. However, the opposite was found in non-dependent smokers, suggesting that e-cigarette use should be discouraged among novice tobacco users. Additionally, although a substantial proportion of young adults used e-cigarettes to help them quit smoking, these self-initiated quit attempts with e-cigarettes were not associated with future smoking reduction or cessation.
This study offers potential support for e-cigarettes as a smoking reduction tool among highly nicotine-dependent young adult conventional smokers, although the extent and nature of this remains unclear. The use of e-cigarettes as a quit aid was not associated with reductions in conventional smoking, consistent with most other quit aids in this sample except for nicotine replacement therapy, which was only effective for the most dependent smokers. Notably, these findings highlight the necessity of accounting for smokers' nicotine dependence levels when examining tobacco use patterns.
电子烟（电子尼古丁输送系统或 ENDS）在青少年中越来越受欢迎。有证据表明，电子烟可能有助于减少危害和戒烟，尽管这些说法仍存在争议。对于尼古丁依赖如何促成电子烟在减少或戒除传统吸烟方面的有效性，我们知之甚少。
对一组年轻人进行了为期 4 年（约 19-23 岁）的调查。采用时变系数模型（VCM）来研究电子烟使用与常规吸烟频率之间的关系，以及这种关系如何因不同尼古丁依赖水平的使用者而异。
在高尼古丁依赖水平的人群中，终生（而非近期）使用电子烟与同时吸烟的传统香烟频率较低有关。然而，非依赖电子烟使用者比从未使用过电子烟的使用者略微更频繁地吸食传统香烟。在最近一次测量中，近一半的电子烟使用者报告使用电子烟来戒烟。对于那些试图通过电子烟戒烟的人来说，电子烟的使用频率与未来传统吸烟频率的降低无关。
这些发现为电子烟可能作为高度尼古丁依赖的年轻成年香烟吸烟者减少吸烟方法提供了可能的支持。然而，在非依赖吸烟者中却发现了相反的结果，这表明应劝阻新手烟草使用者使用电子烟。此外，尽管相当一部分年轻人使用电子烟来帮助他们戒烟，但这些自我发起的电子烟戒烟尝试与未来的吸烟减少或戒烟无关。
本研究为电子烟作为高度尼古丁依赖的年轻成年常规吸烟者的吸烟减少工具提供了潜在支持，尽管其程度和性质尚不清楚。电子烟作为戒烟辅助手段的使用与常规吸烟的减少无关，与该样本中的大多数其他戒烟辅助手段一致，除了尼古丁替代疗法，尼古丁替代疗法仅对最依赖的吸烟者有效。值得注意的是，这些发现强调了在研究烟草使用模式时，需要考虑到吸烟者的尼古丁依赖水平。
