Reacción a "Vaping among young people is associated with higher subsequent consumption of tobacco, marijuana or alcohol"

This umbrella review brings together in one place issues relating to young people, e-cigarettes and health effects. It reported on 56 systematic reviews of which 53 were rated critically low or low quality, meaning authors should be extremely cautious before making any conclusions.

The authors reported that the reviews found consistently that vaping was associated with subsequent smoking. This replicates the findings of many previous reviews and indeed research I have been involved in. However, the authors incorrectly state that this supports ‘a causal relationship’ in other words that vaping causes smoking (the so-called ‘gateway’ effect). It is well-established that consistency does not mean causality. In this case, individual-level studies that were the focus of these reviews do not take into account all the possible influences on these behaviours, such as being sensation-seeking or impulsive which might make young people more likely to vape and to smoke. Our research also showed the opposite relationship - that trying a tobacco cigarette was associated with subsequent vaping. Indeed, a recent well conducted systematic review published using gold standard methods, reported a similar finding to the umbrella review for individual-level studies - but it found the opposite in studies examining population-level trends in vaping and smoking, so as youth vaping increased in a population, smoking reduced. Given these authors also talked about limited evidence, we need more and better research to be able to make confident conclusions about the relationship between youth e-cigarette use and health outcomes.

The umbrella review’s finding of a relationship between vaping and subsequent substance use suffers from similar issues. Furthermore, findings on other health outcomes were often examined in cross-sectional studies, which take a snapshot of people at one point in time. These simply show a relationship, such as that between vaping and mental health but cannot say anything about what came first, and hence whether vaping caused the mental health condition or whether the mental health condition caused young people to vape.

Nevertheless, we are all keen to protect young people’s health and concerns about youth smoking and vaping have prompted the government to introduce its Tobacco & Vapes Bill and its passage through Parliament should be accelerated.