Trends in Youth Smoking and E-Cigarette Use

The use of electronic nicotine delivery systems (ENDS, including e-cigarettes) among young smokers is not related to an increase or decrease in smoking.

The widespread use of ENDS among young adults (YAs) aged 18 to 24 in the United States raises questions about how these products will affect future tobacco and nicotine users.

A recent literature review by the National Academies of Sciences, Engineering, and Medicine (NASEM) concluded that while the harm to adult smokers may be reduced with ENDS use, it could actually cause harm if more non-smokers, especially young people, are induced to start smoking as a result. The authors of the NASEM report found "moderate evidence" supporting the assertion that "the use of e-cigarettes increases the frequency and intensity of later smoking." A new study published in JAMA Network Open recently explored this issue: Is there a link between the use of ENDS and changes in smoking frequency or intensity among young smokers?
 

This cohort study utilized three waves of data from the Population Assessment of Tobacco and Health (PATH) study (2013-2014, 2014-2015, and 2015-2016), an ongoing longitudinal cohort study of adults and youth. A total of 1,096 YAs (ages 18-24) were included in the analysis from August 2018 to October 2019.

Among the 1,096 YA sample, 609 (55.6%) were young women, 698 (63.7%) were white, and 276 (25.2%) were Hispanic. The average (SD) age was 21.4 (1.9) years, and 584 (53.3%) had at least completed college. Among them, 214 (19.5%) were cannabis users in the past 30 days, and 161 (14.75%) smoked daily in the past 30 days. In the first wave, the average smoking frequency and intensity increased with the increase in smoking frequency in the past 30 days until the end of the second wave. In the third wave, the average change in smoking frequency was close to zero across all groups (0.4 - 0.7 days). From the second wave to the third wave, the average change in smoking intensity varied more, from 5.0 cigarettes (at the end of the initial phase) to 22.6 or more cigarettes (at the end of the past 30 days of using 6 days).
 

Description of the sample size and exposure status of the Youth Analysis in Waves 1 - 3 of the Tobacco Health Population Assessment Study

Link between ENDS use at the end of Wave 2 and changes in smoking in Wave 3:

In the PSM dataset, the number of smoking days in the past 30 days increased by 0.33 to 1.64 days, depending on the definition of ENDS use in Wave 2; these changes were unrelated to ENDS use in Wave 2. Between Waves 2 and 3, there was also an increase in smoking intensity in the past 30 days, especially among YAs who used tobacco sticks for 6 days or more in the past 30 days; however, these estimates were not associated with smokers in Wave 2. Those who used tobacco sticks for 6 days or more in the past 30 days had an increase of 44.4 cigarettes compared to those who had never used tobacco sticks, but this increase was not statistically significant.
 

Unweighted associations between different levels of ENDS exposure in Wave 2 and changes in smoking frequency and intensity in Wave 3

In this study, the use of electronic nicotine delivery systems among YA smokers in the year from 2014 to 2015 was not related to an increase or decrease in smoking. However, with the rapid development of the e-cigarette market, future use of e-cigarettes may take a different direction.

References:

Pearson JL, Sharma E, Rui N, et al. Association of Electronic Nicotine Delivery System Use With Cigarette Smoking Progression or Reduction Among Young Adults. JAMA Netw Open. 2020;3(11):e2015893. doi:10.1001/jamanetworkopen.2020.15893