Background: The aim of this study was to investigate long-term trends in smoking prevalence and its socioeconomic inequalities in Korea. Methods: Data were collected from 10 rounds of the Social Survey of Statistics Korea between 1992 and 2016. A total of 524,866 men and women aged 19 or over were analyzed. Age-adjusted smoking prevalence was calculated according to three major socioeconomic position indicators: education, occupational class, and income. The prevalence difference, prevalence ratio, slope index of inequality (SII), and relative index of inequality (RII) were calculated to examine the magnitude of inequality in smoking. Results: Smoking prevalence among men decreased from 71.7% in 1992 to 39.7% in 2016, while smoking prevalence among women decreased from 6.5% in 1992 to 3.3% in 2016. Socioeconomic inequalities in smoking prevalence according to the three socioeconomic position indicators were found in both men and women throughout the study period. In general, absolute and relative socioeconomic inequalities in smoking, measured by prevalence difference and prevalence ratio for education and occupational class, widened during the study period among Korean men and women. In men, the SII for income increased from 7.6% in 1999 to 10.8% in 2016 and the RII for income also increased from 1.11 in 1999 to 1.31 in 2016. In women, the SII for income increased from 0.1% in 1999 to 2.4% in 2016 and the RII for income increased from 1.39 in 1999 to 2.25 in 2016. Conclusion: Pro-rich socioeconomic inequalities in smoking prevalence were found in men and women. Socioeconomic inequalities in smoking have increased in parallel with the implementation of tobacco control policies. Tobacco control policies should be developed to decrease socioeconomic inequalities in cigarette use in Korea.

The aim of this study was to investigate cancer patients' utilization of tertiary hospitals in Seoul before and after the benefit expansion policy implemented in 2013. This was a before-and-after study using claims data of the Korean National Health Insurance Service from 2011 to 2016. The unit of analysis was inpatient episodes, and inpatient episodes involving a malignant neoplasm (International Classification of Diseases, Tenth Revision codes: C00-C97) were included in this study. The total sample (n=5 565 076) was divided into incident cases and prevalent cases according to medical use due to cancer in prior years. The tertiary hospitals in Seoul were divided into two groups (the five largest hospitals and the other tertiary hospitals in Seoul). The proportions of the incident and prevalent episodes occurring in tertiary hospitals in Seoul were 34.9% and 37.2%, respectively, of which more than 70% occurred in the five largest hospitals in Seoul. Utilization of tertiary hospitals in Seoul was higher for inpatient episodes involving cancer surgery, patients with a higher income, patients living in areas close to Seoul, and patients living in areas without a metropolitan city. The utilization of the five largest hospitals increased by 2 percentage points after the policy went into effect. The utilization of tertiary hospitals in Seoul was concentrated among the five largest hospitals. Future research is necessary to identify the consequences of this utilization pattern.

Objectives The difference between income quintiles in health is relatively well accepted by the general public as a measure of health inequality. However, the slope index of inequality (SII) in health reflects the patterns of all social groups, including the middle 60%, and it could therefore be considered more academically desirable. If these two measures are closely correlated, the widespread use of the difference between income quintiles in health would be better supported. This study was conducted to compare differences between income quintiles in life expectancy (LE) and healthy life expectancy (HLE) with the SII. Design Cross-sectional comparison using correlational analysis of district level income differences in LE and HLE with associated SII. Setting All 252 subnational districts of Korea. Participants A total of 342 439 895 subjects (171 287 729 men, 171 152 166 women) and 1 753 476 deaths (970 928 men, 782 548 women) between 2008 and 2014 were analysed. Primary and secondary outcome measures Difference in LE and HLE by income quintile and associated SII. Results The Pearson correlation coefficients between differences between income quintiles and the SII were generally high: 0.97 (95% CI 0.96 to 0.98) for LE in men and women combined and 0.96 (95% CI 0.94 to 0.97) for HLE in men and women combined. In most districts, the SII was greater than the difference between income quintiles. Conclusion Differences between income quintiles were closely correlated with the SII. The widespread use of differences between income quintiles in health as a measure of health inequality may be preferable for communicating results of health inequality measurements to the public.

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.

This study examined trends in inequality in cigarette smoking prevalence by income according to recent anti-smoking policies in Korea. The data used in this study were drawn from three nationally representative surveys, the Korea National Health and Nutrition Examination Survey, the Korea Community Health Survey, and the Social Survey of Statistics Korea. We calculated the age-standardized smoking prevalence, the slope index of inequality, and the relative index of inequality by income level as a socioeconomic position indicator. Smoking prevalence among men decreased during the study period, but the downward trend became especially pronounced in 2015, when the tobacco price was substantially increased. Inequalities in cigarette smoking by income were evident in both genders over the study period in all three national surveys examined. Absolute inequality tended to decrease between 2014 and 2015 among men. Absolute and relative inequality by income decreased between 2008 and 2016 in women aged 30-59, except between 2014 and 2015. The recent anti-smoking policies in Korea resulted in a downward trend in smoking prevalence among men, but not in relative inequality, throughout the study period. Absolute inequality decreased over the study period among men aged 30-59. A more aggressive tax policy is warranted to further reduce socioeconomic inequalities in smoking in young adults in Korea.

Kim I, et al. J Korean Med Sci. 2019 May;34(23):e168. https://doi.org/10.3346/jkms.2019.34.e168