E-cigarette use in England 2014-17 as a function of socio-economic profile.

Background and Aims: E-cigarettes have the potential either to decrease or increase health inequalities, depending on socio-economic differences in their use and effectiveness. This paper estimated the associations between socio-economic status (SES) and e-cigarette use and examined whether these associations changed between 2014 and 2017.
Design: A monthly repeat cross-sectional household survey of adults (16+) between January 2014 and December 2017. This time-period was chosen given that the prevalence of e-cigarette use stabilized in England in late 2013.
Setting: England.
Participants: Participants in the Smoking Toolkit Study, a monthly household survey of smoking and smoking cessation among adults (n = 81 063; mean age = 48.4 years, 49% were women) in England. Subsets included past year smokers (n = 16 232; mean age = 42.8, 46% women), smokers during a quit attempt (n = 5305, mean age = 40.6, 49% women) and long-term ex-smokers (n = 13 562, mean age = 59.3, 44% women).
Measurements: The outcome measure for the analyses was current e-cigarette use. We also included smokers during a quit attempt where use of an e-cigarette during the most recent quit attempt was the outcome measure. Social grade based on occupation was the SES explanatory variable, using the National Readership Survey classification system of AB (higher and intermediate managerial, administrative and professional), C1 (supervisory, clerical and junior managerial, administrative and professional), C2 (skilled manual workers), D (semi-skilled and unskilled manual workers) and E (state pensioners, casual and lowest-grade workers, unemployed with state benefits only). The analyses were stratified by year to assess the changes in these associations over time.
Findings: Among past-year smokers, lower SES groups had lower overall odds of e-cigarette use compared with the highest SES group AB (D: odds ratio = 0.53, 95% confidence interval = 0.40-0.71; E: 0.67, 0.50-0.89). These differences in e-cigarette use reduced over time. The use of e-cigarettes during a quit attempt showed no clear temporal or socio-economic patterns. Among long-term ex-smokers, use of e-cigarettes increased from 2014 to 2017 among all groups and use was more likely in SES groups C2 (2.03, 1.08-3.96) and D (2.29, 1.13-4.70) compared with AB.
Conclusions: From 2014 to 2017 in England, e-cigarette use was greater among smokers from higher compared with lower socio-economic status (SES) groups, but this difference attenuated over time. Use during a quit attempt was similar throughout SES groups. Use by long-term ex-smokers increased over time among all groups and was consistently more common in lower SES groups.
(© 2018 Society for the Study of Addiction.)