Examining differences in real-world effectiveness of e-cigarettes for smoking cessation by source of purchase in England: an observational study of different contexts before and after the COVID-19 pandemic.

Abstract

The effectiveness of e-cigarettes for smoking cessation may differ by source of purchase. The changing influence of self-selection on purchase location caused by COVID-19 pandemic-related vape shop closures means we can examine the association between smoking abstinence e-cigarette use by purchase source and test for moderation of this association by the timing of the pandemic. Repeat-cross-sectional nationally representative surveys, conducted between January-2017 and August-2023. Participants (N=1,284; ≥18y, 46.9% women) who made a past-year quit attempt, used an e-cigarette in their most recent attempt, currently vaping and provided data on the purchase source were included. The association between e-cigarette purchase source and continuous abstinence following the most recent quit attempt was assessed with adjusted regression, including an interaction between the timing of pandemic restrictions (March-2020 through January-2022). Overall, 48.1% usually purchasing their e-cigarettes from vape shops, declining from 53.6% pre-pandemic to 40.6% during the pandemic. There was inconclusive evidence that those purchasing from vape shops had greater odds of quitting smoking (ORadj=1.25, 95%CI 0.92-1.76). The association between purchase source and successful quitting did not depend upon whether purchasing occurred before or during the pandemic (F=0.08, pinteraction=0.774; pre-pandemic: ORadj=1.23, 0.79-1.91; and pandemic: ORadj=1.29, 0.81-2.06). More data are needed to conclusively determine whether purchasing from a specialist vape shop increases smoking cessation. Given the changing influence of self-selection on purchase location caused by the pandemic, the similar associations between purchase source and quit success across both periods suggests it is unlikely an artefact of unmeasured confounding. It is important to know if where e-cigarettes are purchased can increase their effectiveness for smoking cessation. While we found a positive association between purchasing from a specialist vape shop and abstinence rates, the results were inconclusive. Further studies are required to establish whether purchasing from specialist vape shops improves smoking cessation outcomes compared with other purchase sources.