07 February 2025
Conclusions
Current e-cigarette use in respondents reporting former cigarette smoking was associated with a higher risk of COPD prevalence compared to never e-cigarette use in the same population even after accounting for sociodemographic variables, medical comorbidities, and important smoking variables including cigarette pack years, cigarette smoking age of onset, and time since quit for cigarettes. These findings depended in part on how cigarette smoking history was modeled. This finding raises questions about previous studies that reported association but included only current or former cigarette smoking status as covariates. Future longitudinal studies could provide more robust insights into these associations, better controlling for confounders, and establishing clearer causal relationships. As such, more longitudinal investigation into the long-term health effects of e-cigarette products is needed, and randomized trials may be necessary to advise individuals about respiratory risks associated with e-cigarettes as a means for smoking cessation.