Introduction ‘Stealth vaping’ is the practice of vaping discreetly in places where electronic cigarette (e-cigarette) use is prohibited. While anecdotal evidence suggests that stealth vaping is common, there have been no formal studies of the behaviour. The purpose of this study is to examine stealth vaping behaviour among experienced e-cigarette users.

Methods Data were collected from the follow-up survey of a large longitudinal cohort study of adult experienced e-cigarette users conducted in January 2017. To measure stealth vaping behaviour, participants were asked ‘Have you ever ‘stealth vaped’, that is to say, used an e-cig in a public place where it was not approved and attempted to conceal your e-cig use? (yes/no)’. Participants indicating yes completed additional questions about the frequency of stealth vaping and were asked to select all the locations where they commonly stealth vape. Frequencies were used to examine the overall prevalence, frequency and common locations for stealth vaping. A logistic regression model was run to predict stealth vaping.

Results Approximately two-thirds (64.3%, n=297/462) of the sample reported ever stealth vaping, of which 52.5% (n=156/297) reported stealth vaping in the past week. Among stealth vapers (n=297), 31% reported owning a smaller device solely for stealth vaping. The most common places to stealth vape included at work (46.8%), followed by bars/nightclubs (42.1%), restaurants (37.7%), at the movies (35.4%) and in airports/on airplanes (11.7%). Predictors of stealth vaping were greater dependence and owning a smaller device solely for stealth vaping.

Conclusions Stealth vaping is a common behaviour for many experienced e-cigarette users. More research is needed to understand the reasons for stealth vaping and its potential health and safety implications. This information could help researchers and regulators to design interventions to minimise the public health impact of stealth vaping.