Despite decades of progress, vaping has reignited teen smoking risk, putting today's e-cigarette users back where youth started in 1974.
Study: Risk of adolescent cigarette use in three UK birth cohorts before and after e-cigarettes. Image credit: Aleksandr Yu/Shutterstock.com
Introduction
Teenage smoking has declined sharply over the past 25 years, due mainly to successful anti-smoking policies and efforts, coupled with rising education levels and lower smoking rates among parents. However, electronic cigarette (e-cigarette) use (vaping) has become hugely popular among modern youth. A study published in BMJ Journals indicates that adolescent vaping is associated with increased tobacco cigarette use and may lead to dual use (both vaping and cigarette smoking) later in life.
However, while vaping is associated with a greater risk of smoking, the direction of causality remains unclear.
The current study explored whether adolescent vaping is linked to rising or falling smoking rates among youth. It compared the chances of cigarette smoking across three cohorts spanning 1974 to 2018. These include three generations of adolescents, beginning with those who were vaping-naïve and unexposed to tobacco control policies and interventions, and ending with more recent generations.
About the study
The data came from three UK birth cohorts (1958, 1970, and 2001). This long period made it possible to trace the fall in adolescent cigarette smoking over time, while recording the association of rising trends with e-cigarette use (vaping) in the youngest cohort. The latest cohort was the Millennium Cohort Study (MCS), during whose childhood vapes appeared on the market.
In contrast, the National Child Development Study (NCDS) includes adolescents who lived through the period when smoking was at its peak. The British Cohort Study (BCS) consists of those exposed to widespread smoking in childhood, but to vaping only in their 40s.
Adolescent cigarette smoking in 1974, 1986, and 2018 was captured by self-report at age 16, 16, and 17 years, respectively, in each cohort. Vaping at age 17 was also captured by self-report in the MCS.
Study findings
In 1974, 33% of teens smoked, falling to 25% in 1986 and to a low of 12% over the next two decades, by 2018.
Interestingly, all three cohorts had similar childhood risk factors for smoking in later adolescence. These included low school engagement, drinking by age 16 or 17, verbal ability, and externalizing behaviors reported by the mother or primary caregiver. The latter included being fidgety, disobedient, restless, and hot-tempered.
While 94% of teens in the NCDS cohort said they had drunk alcohol by 16 or 17, this fell somewhat to 83% in the MCS cohort. Smoking by parents fell from 70% to 27%, respectively. Maternal tobacco use in pregnancy also declined in the latest cohort.
In each cohort, drinking by 16 or 17 predicted a three- to four-fold smoking risk, compared to non-drinkers. More externalizing behavior increased the odds by up to 34%. Poor school engagement and low verbal ability were also universally associated with higher smoking risk. Parental jobs, education, and smoking habits had less consistent effects.
For the youngest cohort, the presence of vaping stood out as a determinant of cigarette smoking. Youngsters in the MCS cohort who did not vape had a 1.4% chance of smoking, vs 33% among current vaping youth. Surprisingly, this is higher than the risk in the NCDS (32%) or BCS (22%) cohorts.
In other words, MCS adolescents who currently vape have a smoking risk at the level of 1974, well before anti-tobacco efforts took off. Even those who had only experimented with e-cigarettes had a 12.7% risk of smoking, compared to 1.4% among those who had never used them.
Compared to past or experimental users, current vapers had 3.3 times greater odds of smoking cigarettes, while never-users had 90% lower odds of smoking.
Conclusions
It is vital to examine the role of vaping in adolescence in later decisions to smoke or potentially engage in dual use.
The historic decline in smoking is visible in the most recent birth cohort, but it is strikingly reversed among current e-cigarette users, who make up about 11% of the cohort. Smoking prevalence remained very low among the rest of the cohort, particularly those who never vaped.
E-cigarette use has emerged as a strong marker for increased smoking risk, even though vaping was initially thought of as having little danger to youth.
The authors caution that the study is observational and cannot determine causality, especially since the timing of vaping versus smoking initiation is not established. Yet the consistency of trends across the three cohorts strengthens confidence in the patterns observed.
Given that the current increase in smoking risk is in contrast to the improvement in other risk factors, the findings suggest that vaping may be undermining the progress of successive public health and anti-tobacco policies implemented over five decades.
“Policy and prevention should seek to prevent adolescent nicotine exposure via both electronic and combustible cigarettes.” Youngsters who vape should be targeted explicitly by tobacco control interventions, coupled with strong anti-vaping preventive efforts.
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