Hammond David, Reid Jessica L, Cole Adam G, Leatherdale Scott T
School of Public Health and Health Systems, University of Waterloo, Waterloo, Ont.
CMAJ. 2017 Oct 30;189(43):E1328-E1336. doi: 10.1503/cmaj.161002.
The influence of e-cigarette use on smoking initiation is a highly controversial issue, with limited longitudinal data available for examining temporal associations. We examined e-cigarette use and its association with cigarette-smoking initiation at 1-year follow-up within a large cohort of Canadian secondary school students.
We analyzed data from students in grades 9-12 who participated in 2 waves of COMPASS, a cohort study of purposefully sampled secondary schools in Ontario and Alberta, Canada, at baseline (2013/14) and 1-year follow-up (2014/15). We assessed cigarette smoking and e-cigarette use at baseline and follow-up using self-completed surveys. We used generalized linear mixed-effects models to examine correlates of past 30-day e-cigarette use at baseline and smoking initiation between waves within the longitudinal sample.
Past 30-day e-cigarette use increased from 2013/14 to 2014/15 (7.2% v. 9.7%, < 0.001), whereas past 30-day cigarette smoking decreased slightly (11.4% v. 10.8%, = 0.02). Among the 44 163 students evaluated at baseline, past 30-day e-cigarette use was strongly associated with smoking status and smoking susceptibility. In the longitudinal sample ( = 19 130), past 30-day use of e-cigarettes at baseline was associated with initiation of smoking a whole cigarette (adjusted odds ratio [OR] 2.12, 95% confidence interval [CI] 1.68-2.66) and with initiation of daily smoking (adjusted OR 1.79, 95% CI 1.41-2.28) at follow-up.
E-cigarette use was strongly associated with cigarette smoking behaviour, including smoking initiation at follow-up. The causal nature of this association remains unclear, because common factors underlying the use of both e-cigarettes and conventional cigarettes may also account for the temporal order of initiation.
电子烟使用对吸烟起始的影响是一个极具争议的问题，可用于检验时间关联的纵向数据有限。我们在一大群加拿大中学生中，研究了电子烟使用情况及其与1年随访期内吸烟起始的关联。
我们分析了9至12年级学生的数据，这些学生参与了COMPASS研究的两个阶段，这是一项对加拿大安大略省和艾伯塔省有目的抽样的中学进行的队列研究，在基线期（2013/14）和1年随访期（2014/15）进行。我们使用自我完成的调查问卷评估基线期和随访期的吸烟及电子烟使用情况。我们使用广义线性混合效应模型来研究纵向样本中基线期过去30天电子烟使用的相关因素以及各阶段之间的吸烟起始情况。
过去30天的电子烟使用从2013/14年到2014/15年有所增加（7.2%对9.7%，<0.001），而过去30天的吸烟情况略有下降（11.4%对10.8%，=0.02）。在基线期评估的44163名学生中，过去30天的电子烟使用与吸烟状况和吸烟易感性密切相关。在纵向样本（n = 19130）中，基线期过去30天使用电子烟与随访期开始吸整支香烟（调整后的优势比[OR] 2.12，95%置信区间[CI] 1.68 - 2.66）以及开始每日吸烟（调整后的OR 1.79，95% CI 1.41 - 2.28）相关。
电子烟使用与吸烟行为密切相关，包括随访期的吸烟起始。这种关联的因果性质尚不清楚，因为电子烟和传统香烟使用背后的共同因素也可能解释起始的时间顺序。
