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

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.