Analysis suggests e-cigarette use may be linked to lower rates of smoking

Key takeaways:

• As e-cigarette use increased on a population level, smoking rates decreased.
• People who used e-cigarettes were more likely to report smoking later in life compared with those who did not vape.

Greater e-cigarette accessibility and use appeared to be associated with lower rates of smoking among young people, according to the results of a systematic review and meta-analysis published in Addiction.

However, the researchers noted that their conclusions were based on very low certainty evidence and future research could yield different results.

“It was striking how different study designs led to very different findings,” Jamie Hartmann-Boyce, MA, DPhil, assistant professor of health policy and management at University of Massachusetts Amherst, told Healio. “Studies that tracked individuals over time consistently found that young people who vaped were more likely to go on to report smoking than people who didn’t vape. However, some studies that tracked populations of young people over time found that increased e-cigarette use was associated with lower smoking rates across populations.”

“Some also found that as youth vaping decreased, subsequent youth smoking went up,” she said.

Hartmann-Boyce and colleagues conducted a systematic review and meta-analysis of 126 studies evaluating the relationship between e-cigarette use and smoking among people aged 29 years or younger.

They pointed out that none of the studies were considered to have a low risk of bias.

Out of 27 population-level studies, 11 had a moderate risk of bias, nine had a serious risk of bias and seven had a critical risk of bias because of confounding evidence and bias in how the researchers reported the results.

Out of 40 tier 1 individual-level studies, 27 had a serious risk of bias and 13 had a critical risk of bias mainly because of missing information about how frequently participants used e-cigarettes.

Most population-level studies demonstrated that e-cigarette availability led to lower rates of smoking. However, two studies found the opposite effect. Additionally, seven studies reported no association or an association that was not statistically significant. Two studies reported that higher rates of e-cigarette use were associated with lower rates of cigarette use.

In contrast, almost all individual-level studies revealed a link between current vaping and future smoking among young people, but the researchers noted it was unclear whether there was a causal relationship.

Ultimately, all of the evidence was considered to be very low certainty, and there are many different ways to interpret the data, Hartmann-Boyce said in a related press release.

“Overall, study findings suggest that vaping may not increase smoking across populations of young people,” Hartmann-Boyce told Healio. “There are many other reasons, of course, to support young people to quite vaping, and research is underway to find out which interventions work best.”

References:

• Begh R, et al. Addiction. 2025;doi:10.1111/add.16773.
• New study fails to show that youth vaping causes future smoking. https://www.eurekalert.org/news-releases/1073339. Published Feb. 11, 2025. Accessed March 5, 2025.