Expert Q&A

Risk Factors for Progression to Daily Cigarette Use in Youths

The use of e-cigarettes and other tobacco products before age 18 years significantly increases the risk of later daily cigarette smoking, according to the results of a study published by the American Academy of Pediatrics.1

To better understand the relationship between youth tobacco use and progression to daily cigarette smoking, the researchers utilized data from the US Population Assessment of Tobacco and Health (PATH) study. Included in their analysis were 15,826 participants aged between 12 and 24 years who completed 4 survey waves over 4 years.

In addition to youth who experiment with e-cigarettes being 3 times more likely to progress to daily cigarette smoking, the results revealed that the age of first use and the number of tobacco products tried were predictors of later daily use.

To learn more about these study findings, Consultant360 reached out to lead study author John Pierce, PhD, who is a professor emeritus at the Herbert Wertheim School of Public Health and Human Longevity Science and UC San Diego Moores Cancer Center.

Consultant360: Your study examined the relationship between the use of e-cigarettes and other tobacco products on the progression to daily cigarette smoking among adolescents and young adults. How did this study objective come about?

John Pierce PhD: In 2018, we published a paper2 that showed that e-cigarette advertising was associated with increased experimentation with e-cigarettes and with increased experimentation with cigarettes.  However, we recognized that experimentation with cigarettes was not the real problem—it was important to keep following this sample and see whether e-cigarettes led people to become addicted smokers. This was the direct precursor to our work on the Pediatrics paper.

C360: The results of your study indicated that while only 12% of participants were daily tobacco smokers at wave 4, 70% of these participants were daily cigarette smokers. What does this finding mean for clinical practice and how pediatricians can potentially intervene?

JP: We studied young people aged 12 to 24 years over a period of 4 years, when they were aged 16 to 28 years. Daily tobacco use increased dramatically with age, from 6.3% at age 15 to 17 years to a high of 26% at age 25 to 28 years (see Table 4 in the paper).

Many participants from our sample had not yet gone through the age window for becoming a daily tobacco user.  From Table 4, we see that the only product that had daily users increasing with age was cigarettes. So, despite the fact that e-cigarette advertising got them to experiment with e-cigarettes, the vast majority switched to become addicted to cigarettes. Thus, for clinicians who are focused on preventing dependence on cigarettes with all their health consequences, the message has to be that experimentation with e-cigarettes is not safe and appears to be a new gateway to cigarette smoking. The recent high rates of experimentation with e-cigarettes portend a turn-around in the decline in young adult cigarette smoking that we have had in the United States for the past 20 years – ever since we managed to restrict cigarette advertising to youth

C360: You and your team also found that the risk of later cigarette smoking was 3 times higher in those who used e-cigarettes. What do you believe causes individuals to switch from other tobacco products to cigarettes, when it is the most harmful type of tobacco product?

JP: We know that adolescents and young adults are more concerned with image and being in tune with their peers than they are on the long-term health effects of what they are doing. Most feel that they will quit within a few years anyway. They do not recognize the addictiveness of nicotine or the difficulties that many people have in trying to quit.  It would appear that for many young people, e-cigarettes are not as fulfilling as cigarettes.  Presumably, when they tried cigarettes, they found that they got nicotine in a more rewarding fashion, leading them to switch. This is a subject of ongoing research.

C360: In your opinion, do you think increasing taxes on tobacco products or banning them from shelves will improve the smoking rate among youths?

JP: We know that prohibition led to smuggling rather than a major decline in people who drank alcohol. We also know that Australia has rapidly ramped up cigarette taxes so that a pack of cigarettes is now more than $40, and they have not seen a faster decline in smoking than in places like California. What we have been experiencing is the consequences of us allowing unfettered e-cigarette advertising. Until we are prepared to restrict how e-cigarettes are advertised, we will continue to see high experimentation rates, as demonstrated in our 2018 JAMA Pediatrics paper.2

C360: How does your study contribute to the existing literature on the topic?

JP: This is the first evidence proving that the huge increase in experimentation with e-cigarettes is going to have major health consequences, as so many of these young experimenters switch to become dependent cigarette smokers. And we know that we have not been too successful in helping dependent cigarette smokers quit.  We have proven elsewhere3 that e-cigarettes have not been useful as a potential cessation aid. So once these young people become addicted to cigarettes, they will probably be long-term cigarette smokers and experience the known health consequences.

C360: What are the next steps for research in this area?

JP: The PATH study is continuing to follow this very large nationally representative sample of US residents.  We are focused on analyzing this amazing dataset to identify influences on initiation, progression, and cessation of tobacco products and whether switching between products has any long-term benefit. The PATH study has a large biomarker collection as well as detailed health histories.



  1. Pierce JP, Chen R, Leas EC, et al. Use of e-cigarettes and other tobacco products and progression to daily cigarette smoking. Pediatrics. 2021;147(2):e2020025122. doi:/10.1542/peds.2020-025122
  2. Pierce JP, Sargent JD, Portnoy DB, et al. Association between receptivity to tobacco advertising and progression to tobacco use in youth and young adults in the PATH study. JAMA Pediatr. 2018;172(5):444-451. doi:10.1001/jamapediatrics.2017.5756
  3. Pierce JP, Benmarhnia T, Chen R, et al. Role of e-cigarettes and pharmacotherapy during attempts to quit cigarette smoking: the PATH study 2013-16. PLoS One. Published online September 2, 2020.