The prevalence of vaping in older teens stayed fairly steady in England between 2017 and 2018 while it increased in Canada and the US; and over that period smoking prevalence among older teens barely increased in England and didn’t change in the US while it rose sharply in Canada, new research has shown. The authors of the study*, published today in The BMJ, said this could be linked to England’s mandatory limits on the nicotine concentration of e-liquids and greater restrictions on marketing. They called for close monitoring of the rapidly evolving vaping market and the emergence of nicotine salt-based products.
The international research team said that although vaping is probably a less harmful method of nicotine delivery than inhaling smoke from combustible cigarettes, and e-cigarettes might help existing smokers to quit, there is also much concern that vaping could undermine reductions in smoking among young people. They noted that previous research, including from prospective cohort studies, has shown “a robust association between smoking and vaping … showing that young people who vape have an increased risk of subsequent smoking, and vice versa”.
They examined differences in vaping and smoking prevalence among adolescents in Canada, England and the US because this age group captures a substantial proportion of both vaping and smoking initiation in all three countries, and because the countries have different regulatory systems; they wanted to look in particular at whether changes to the Canadian vaping market, as a result of the new regulatory framework in 2018, were associated with changes in the prevalence of smoking or vaping.
Through online surveys, they recruited national samples of 16-19 year-olds in 2017 and 2018, from commercial panels in Canada (n=7891), England (n=7897), and the US (n=8140). They assessed prevalence of vaping and smoking for use ever, in the past 30 days, in the past week, and on 15 days or more in the past month. They also assessed use of JUUL (a nicotine salt-based electronic cigarette with high nicotine concentration) and usual vaping brands. They then examined differences in vaping and smoking between countries and over time, using logistic regression models.
They reported that the prevalence of vaping in the past 30 days, in the past week, and on 15 days or more in the past month increased significantly in Canada and the US between 2017 and 2018, including among non-smokers and experimental smokers, but there were no changes in England. Smoking prevalence also increased significantly for all measures in Canada, with modest (but statistically non-significant) increases in England, and no changes in the US. The percentage of ever-vapers who reported more frequent vaping also increased significantly, in Canada and the US, but not in England. They added that the use of JUUL increased in all countries, particularly the US and Canada – for example, the proportion of current vapers in the US who cited JUUL as their usual brand increased threefold between 2017 and 2018.
The study authors said their results support the widely held belief that young people have contributed to the increase in use of JUUL and the larger market wide shift to nicotine salt-vaping products; and they pointed out that, in contrast, they saw few differences among adolescents in England, where there are mandatory limits on the nicotine concentration of e-liquids and greater restrictions on marketing.
They added: “It is unfortunate that the characteristics that enhance the effectiveness of e-cigarettes as smoking cessation aids – namely, efficient nicotine delivery – also increase their potential to promote addiction among young people,” and concluded: “Finding the optimal regulatory balance that provides smokers with reasonable access to effective products, while restricting features of such products that appeal to adolescents, represents a priority for tobacco control, and for public health more generally.”
The author of an accompanying editorial** looking at this and two other studies on tobacco control, in the same issue of The BMJ, said: “Taken together, these new studies emphasise the value of comparative research for tobacco control across different countries. They also warn against complacency in our attempts to address smoking, now and in the future.” She argued that continued investment in international tobacco control is more important than ever, particularly in low- and middle-income countries with limited capacity to combat industry attempts to delay or derail public health policies.
*Hammond D, Reid JL, Rynard VL, et al. Prevalence of vaping and smoking among adolescents in Canada, England, and the United States: repeat national cross sectional surveys. BMJ 2019; 365: l2219 doi: 10.1136/bmj.l2219
**Bauld L. Editorial: Tobacco control: new resources, existing treaties, and emerging challenges. BMJ 2019; 365: l4161 doi: 10.1136/bmj.l4161