Background: Few studies have been performed on electronic cigarette (e-cigarette) use among Korean adults with no history of combustible cigarette (CC) use. Methods: We used data from the Korea Community Health Survey (2014-2017) to analyze factors associated with e-cigarette ever use among adults with no history of CC use. Multivariate logistic regression analysis was performed to evaluate the relationship between ever use of e-cigarettes and never use of CCs after adjusting for sociodemographic and health behavior factors. Results: Among 579,815 participants with never use of CCs, 971 (0.2%) had ever used e-cigarettes. The odds ratios (ORs) for ever use of e-cigarettes were higher in individuals at a younger age [OR for age 19-34 years was 9.53 than that for age ≥ 65 years, 95% confidence interval (CI) 4.11-22.12], heavy alcohol consumers (OR 1.94, 95% CI 1.54-2.46), those with depressive symptoms (OR 2.36, 95% CI 1.62-3.44), those with poor general health (OR 1.39, 95% CI 1.10-1.75), and those with diabetes (OR 2.27, 95% CI 1.36-3.80). However, the ORs for ever use of e-cigarettes were lower in females (OR 0.11, 95% CI 0.08-0.14), those with low physical activity (OR 0.73, 95% CI 0.56-0.95), and those with hypertension (OR 0.59, 95% CI 0.39-0.89). Conclusions: Ever use of e-cigarette was not common among never users of CCs. However, it was more prevalent in younger individuals, males, and those with poor health and health habits. These factors must be considered while establishing tobacco control policies.

Introduction: Work schedules and working hours are known to affect the incidence of cancer, heart disease, and cardiovascular disease and are associated with unhealthy behaviors. This study evaluated the association between smoking rates in Korean adult workers and their work schedules and working hours. Methods: The analysis included data of 15,904 workers aged ≥19 years obtained from the Korea National Health and Nutrition Examination Survey (2013-2017). The work schedule was categorized as day, evening, night, or shift work, and the working hours per week as ≤40 h, 40-50 h, 50-60 h, or >60 h. Associations were assessed using multivariate logistic regression analysis. Results: Current smokers accounted for 27.4% of the included subjects. Women who worked in the evening or at night had significantly higher smoking rates than those who worked during the day [evening work: odds ratio (OR), 1.797; 95% confidence interval (CI), 1.306-2.471; night work: OR, 6.835; 95% CI, 4.075-11.461]. Smoking rates were significantly higher in both men and women who worked >60 h per week (men: OR, 1.328; 95% CI, 1.117-1.578; women: OR, 1.835; 95% CI, 1.247-2.701). Conclusion: The work schedule and working hours of adult workers in Korea influenced their smoking rates. Tobacco control policies for employees should consider the employees' work schedules and working hours.