Socioeconomic Inequalities in e-Cigarette Use in Korea: Comparison with Inequalities in Conventional Cigarette Use Using Two National Surveys.

Socioeconomic inequalities in conventional cigarette smoking are well established in developed countries. The aim of this study was to investigate socioeconomic inequalities in e-cigarette use in Korea, in comparison with inequalities in conventional cigarette use. Data from the Korea National Health and Nutrition Examination Survey (KNHANES) and the Korea Community Health Survey (KCHS) were analyzed. The years of data collected were 2013 to 2016 for the KNHANES and 2014 to 2016 for the KCHS, respectively. The age-adjusted prevalence of ever and current e-cigarette use and conventional cigarette use was calculated according to socioeconomic status indicators, including education, occupation, and income. The prevalence of ever e-cigarette use in men increased from 12.1% in 2013 to 19.2% in 2016 in the KNHANES, and from 13.4% in 2014 to 17.9% in 2016 in the KCHS. Ever and current e-cigarette use was concentrated among current smokers and was much more prevalent among men and also more common among younger age groups in men and women. There was higher prevalences of conventional cigarette use among men and women with less education, manual occupational class and lower income, with the differences more pronounced for women. There was higher ever and current use of e-cigarettes among women with less education, manual occupational class and lower income, but among men there was much less difference in e-cigarette use by these indicators of socio-economic status.