Are people more likely to vape or smoke indoors? A population survey of adults in England.

BACKGROUND:Increasingly, people smoke cigarettes outdoors and avoid exposing bystanders to harm. People may not have the same motivation to vape outdoors since e-cigarettes, unlike cigarettes, do not create side stream emissions and exhaled aerosol contains fewer toxicants than secondhand smoke. This study aims to estimate the prevalence and correlates of vaping and smoking indoors among adults in England. METHODS:Data came from the Health Survey for England 2019, a cross-sectional household survey. Adults who vape or smoke (N=1,530) were asked whether they had vaped or smoked indoors inside the home, car, or other places within the past seven days. Logistic regression was used to estimate prevalence and key correlates of indoor use, including age, sex, presence of adults/children in home, housing tenure and nicotine dependence. RESULTS:People who exclusively vaped were much more likely to use their product indoors than those who exclusively smoked (87.0% versus 52.0%; odds ratio [OR]=6.16, 95% confidence interval [CI]=4.09-9.28). Similarly, people who dual used had higher odds of vaping than smoking indoors (62.1% versus 44.3%; within-person OR=3.76, 95%CI=2.06-6.84). The preference for vaping over smoking indoors was found across different locations, including at home and in cars. Those who were older, highly dependent on nicotine, and lived alone were most prone to use any product indoors. While housing tenure was not strongly associated with vaping indoors, those living in social housing were much more likely to smoke indoors than homeowners. CONCLUSIONS:Adults in England are much more likely to vape than smoke indoors. Age, nicotine dependence, and living alone are strongly associated with both behaviours. IMPLICATIONS:Our results show that people have a strong preference for vaping over smoking indoors, including in the home. Given the high prevalence of vaping indoors, policymakers, landlords and businesses must weigh up the ethics, benefits, and harms of extending smoke-free laws to include e-cigarettes.