Adults who vape but have never become established cigarette smokers report slightly more frequent respiratory symptoms than similar adults who neither smoke nor vape, according to a large cross-sectional survey published in BMC Pulmonary Medicine. The difference was small in absolute terms and fell below the threshold that researchers consider clinically meaningful, but it was statistically consistent across six world regions.

The study, led by Yusuff Adebayo Adebisi and Riccardo Polosa with an international team of co-authors, analysed responses from 1,519 adults without an established cigarette-smoking history, described in the paper as never-established smokers. Of these, 1,005 were exclusive e-cigarette users who had vaped in the past seven days, while 514 comparison participants had no established vaping history and had not vaped in the past seven days. Data were collected between May 2023 and December 2024 through an internet-based survey spanning six world regions.

Respiratory symptoms were measured with the Respiratory Symptom Experience Scale, a questionnaire instrument that yields a numerical symptom-frequency score. On average, vapers scored 1.64 on this scale after statistical adjustment, compared with 1.44 among the non-vaping comparison group. The adjusted mean difference was 0.20 points, with a 95 percent confidence interval of 0.14 to 0.26 and a p-value below 0.001, indicating that the difference was unlikely to be a chance artefact of sampling.

Whether that difference matters in practice is a separate question. The authors compared their estimate against a previously reported minimal clinically important difference of 0.57 points for the same scale. Both the observed adjusted difference of 0.20 and even the upper limit of its confidence interval, 0.26, remained below that threshold. In other words, the statistical analysis cannot rule out a difference large enough to matter clinically, but the most likely estimate sits well under it, and the authors conclude that these cross-sectional findings do not provide evidence of a clinically meaningful difference in symptom frequency.

Because the design was cross-sectional, capturing a snapshot rather than following participants over time, causality cannot be established. People who choose to vape may differ from those who do not in ways that also influence respiratory symptoms, and the survey’s statistical models can adjust for measured factors but not for unmeasured ones. The researchers accounted for age, sex, body mass index, education and employment status in their primary models, and a sensitivity analysis that additionally adjusted for recruitment region slightly attenuated the association to 0.18 points, with a confidence interval of 0.12 to 0.24.

The survey also probed whether the association varied across subgroups. There was no evidence that the difference in symptom scores differed by sex or by age group, suggesting the pattern was broadly similar across these demographic strata rather than concentrated in one segment of the sample.

Device type emerged as one of the more intriguing secondary findings. Users of refillable devices reported lower symptom scores than users of disposable devices, with an adjusted difference of 0.11 points in the direction of fewer symptoms for refillable devices, a result the authors report as statistically significant. However, refillable-device users did not differ significantly from users of pre-filled pods, where the estimated difference of 0.08 points carried a confidence interval spanning zero. This pattern hints that hardware characteristics, such as nicotine delivery, power output or the composition of e-liquids used in different device formats, could be relevant to symptom experience, though the cross-sectional design cannot confirm any mechanism.

Cumulative duration of vaping also showed a relationship with symptoms. Among the vapers, participants with at least two years of cumulative use had higher symptom scores than those with less than two years of use, an adjusted difference of 0.10 points. By contrast, symptom scores did not differ significantly across categories of vaping frequency, with an omnibus p-value of 0.121, suggesting that how often people vaped was less clearly associated with symptoms than how long they had been vaping.

The study addresses a gap in the evidence base. E-cigarettes have become a widespread alternative to combustible tobacco, yet evidence on their respiratory impact among adults without an established smoking history has remained limited, since much existing research focuses on people who smoke or formerly smoked. By restricting the sample to never-established smokers, the design isolates the experience of adults whose respiratory symptoms cannot be attributed to a history of established cigarette smoking, a population of growing public health interest as vaping spreads among people who never took up smoking.

The authors are careful about what the data can and cannot show. The findings indicate modestly more frequent respiratory symptoms among exclusive vapers compared with non-vaping peers, but the magnitude falls short of the accepted clinical threshold, and no causal claim is possible from a single cross-sectional survey. The work, published open access on 3 November 2026, offers a benchmark for future longitudinal studies that could track symptom trajectories over time and clarify whether the small cross-sectional difference grows, shrinks or disappears with longer observation.

Subject of Research: Respiratory symptom frequency among adult exclusive e-cigarette users without an established smoking history, compared with non-vaping adults, in a multiregional cross-sectional survey.

Article Title: Respiratory symptoms among never-established smokers who vape: a multiregional cross-sectional survey of 1,519 adults

Article References: Adebisi, Y. A., Goicoechea, J. Z., Boughner, A., Lee, J. J. C., Mahajan, A., Yeo, K., Sproga, M., Patel, T., Tomaselli, V., Campagna, D., Spicuzza, L., Selya, A., Morjaria, J. B., & Polosa, R. (2026). Respiratory symptoms among never-established smokers who vape: a multiregional cross-sectional survey of 1,519 adults. BMC Pulmonary Medicine. https://doi.org/10.1186/s12890-026-04943-3

Image Credits: AI Generated

DOI: 10.1186/s12890-026-04943-3

Keywords: e-cigarettes, vaping, respiratory symptoms, cross-sectional study, never smokers, BMC Pulmonary Medicine, public health, nicotine, survey research, pulmonary medicine, Respiratory, symptoms