The association of women's experience of abuse in childhood with depression during pregnancy and the role of emotional support as a moderator.

BACKGROUND: This study aimed to examine the prevalence of antenatal depression and experience of abuse during childhood, to analyze the association between having experienced childhood abuse and depression during pregnancy, and to explore the role of emotional support as a moderator of that association. METHODS: In total, 44,770 pregnant women were analyzed from the self-administered registry for risk assessment at community public health centers in Seoul, Republic of Korea, for home visiting service provision between 2015 and 2019. The Edinburgh Postnatal Depression Scale (EPDS) was applied for the assessment of depression. The adjusted effects of childhood abuse experience on antepartum depression according to emotional support as an effect moderator were estimated. RESULTS: Depression was present in 2,451 pregnant women (5.5%), and 1,506 (3.4%) reported having experienced physical, emotional, or sexual abuse in childhood. After adjustment of covariates, pregnant women who had experienced abuse during childhood had EPDS scores 2.79 points higher than pregnant women without such experiences, and those who lacked emotional support during adulthood had 4.96 points higher than their counterparts. The difference in EPDS scores based on childhood abuse experience among women who reported emotional support (2.86) was larger than the difference in EPDS scores among those with no emotional support (1.91) (P for interaction = 0.0106). CONCLUSIONS: The experience of abuse in early life and emotional support in later life are both independently important for understanding antenatal depression in Korean women. More comprehensive emotional support is needed for pregnant women who experienced abuse in childhood.

Comparison of Bayesian Spatiotemporal Models for Small-Area Life Expectancy: A Simulation Study.

The purpose of this study was to assess the precision, uncertainty, and normality of small-area life expectancy estimates calculated using Bayesian spatiotemporal models. We hypothesized 6 scenarios in which all 247 districts of South Korea had the same year-specific female population of 500, 1,000, 2,000, 5,000, 10,000, and 25,000 individuals during the study period (2013-2017). We generated 1,000 hypothetical data sets for each scenario and calculated district-year life expectancies. The precision and uncertainty of life expectancy estimates were compared between 2 Bayesian spatiotemporal models and the traditional method and Bayesian spatial models. We examined the normality of the life expectancy distributions generated by each method and investigated an optimal cutoff value for the comparisons. The Bayesian spatiotemporal models produced precise life expectancy estimates. However, the 95% uncertainty interval contained the true value with a probability of less than 95%. The Bayesian spatiotemporal models violated the normality assumption in scenarios with small population sizes. Therefore, life expectancy comparisons should be conducted using a cutoff value that minimizes false-positive and false-negative rates. We propose 0.8 as a cutoff value for determining the statistical significance of the difference in life expectancy.

Prevalence of intimate partner violence victimization among Korean perinatal women and associated factors.

OBJECTIVE: To determine the prevalence of intimate partner violence (IPV) victimization and the factors associated with IPV during pregnancy and the early postnatal period in Korean community samples. METHODS: We enrolled 5953 pregnant mothers and mothers with young children registered in the Early Life Health Management Program provided by 30 public health centers in Korea between 2020 and 2021. We used the Korean Hurt, Insult, Threaten, and Scream (K-HITS) questionnaire to measure IPV. Sociodemographic, social support, and psychosocial variables were collected using self-administered questionnaires. χ2 tests and multiple logistic regression analyses were conducted using SAS. RESULTS: Using a cut-off score of 6 with K-HITS, the prevalence of IPV was 7.6%. According to multivariable logistic analyses, "have seen domestic violence during childhood or adolescence" (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.95-3.50), unplanned pregnancy (OR 2.18, 95% CI 1.73-2.75), depression during pregnancy (OR 2.17, 95% CI 1.69-2.79), history of receiving treatment for emotional problems (OR 1.53, 95% CI 1.07-2.20), and living in a rural area (OR 1.52, 95% CI 1.01-2.29) increased the odds of IPV. "Having someone who talk to" was protective of IPV (for" "Not having someone to talk to": OR 2.24, 95% CI 1.49-3.35). CONCLUSIONS: Policies to prevent and address IPV during the perinatal period are urgently needed in Korea.

Disability type-specific mortality patterns and life expectancy among disabled people in South Korea using 10-year combined data between 2008 and 2017.

People with disabilities have a higher mortality risk than non-disabled people. However, mortality patterns and life expectancy according to disability types are under-researched. This study investigated the sociodemographic characteristics and compared mortality and life expectancy among people with disabilities according to disability type in Korea using 10-year combined data between 2008 and 2017. The National Health Information Database from the National Health Insurance Service covering the total Korean population between 2008 and 2017 was obtained. This study described the age and income distributions of people with disabilities and calculated the mortality rate, proportional mortality ratio, and life expectancy according to disability type. Most disability subgroups had higher average ages than were found for non-disabled people. The proportion of the bottom 20% household income group was also higher in all types of disabilities than in non-disabled people. The crude mortality rate, age-standardized mortality rate, and life expectancy were all worse in people with all types of disabilities than in their non-disabled counterparts, but variations according to disability type were found. The composition of causes of death also varied across disability types. Although all types of disabilities were associated with higher mortality rates and lower life expectancy, the sociodemographic characteristics and mortality and life expectancy patterns differed across types of disability. People with disabilities experienced various health-related problems and financial burdens. Public assistance needs to be strengthened to guarantee adequate income and health care services for people with disabilities, considering their sociodemographic characteristics and mortality patterns.

An analysis of the very high level of maternal distress experienced by South Korean women with young children.

This study was conducted as a part of a larger study to identify the needs of a maternal and early childhood home visit program that the South Korean central government has begun to expand nationwide. This survey measured the distress of mothers with children aged 2 years or younger during the transition into motherhood using the Being a Mother scale (BaM-13) and compared the stress levels for each question with those of existing studies in other countries. The survey results revealed that the mean BaM-13 score of the 350 participants was 17.09 (SD = 6.81), with 87.7% showing very high levels of maternal distress, indicated by a score of 9 or above in BaM-13. The item from the BaM-13 with the highest response rate of 2 or 3 points (sum of the percentage of those who answered 2 and 3 points) was "I have missed the life I had before I became pregnant with this baby/toddler," to which 80.8% of the respondents agreed. The percentage of South Korean mothers who answered 2 or 3 points was higher for every item on the BaM-13 than that of Australian mothers. A comparison of the total BaM-13 score and 3 factors (child experience, adult's experience, and emotional closeness) of the BaM-13 according to the participants' characteristics revealed that discrepancies in women's sociodemographic factors (including smoking and alcohol consumption behaviors) were not significant, whereas differences in the total BaM-13 score and the 3 factors of the BaM-13 according to the mothers' scores on the Edinburgh Postnatal Depression Scale were noticeable. The high level of maternal distress observed in this study should be reflected in the nurse-led maternal and early childhood home visit program that the South Korean central government is expanding across the country.

Is a universal nurse home visiting program possible? A cross-sectional survey of nurse home visitation service needs among pregnant women and mothers with young children.

In 2019, the South Korean government established a plan to develop home visitation services for pregnant women and women with children below the age of 24 months and expand the services nationwide. Therefore, a national survey was needed to provide relevant information for the policy decision of whether to implement universal home visitation services by nurses for families with young children. To determine home visitation service needs in South Korea, 804 women who were pregnant or had children below the age of 24 months were selected as survey participants through stratified random sampling by region reflecting geographical distribution in numbers of births. Of them, 614 responded to survey questionnaires delivered via email. After excluding surveys with too short of a response time, extreme values, and incomplete answers, 500 participants' responses were analyzed. Participants indicated whether they supported the provision of home visitation services and whether they were willing to utilize home visitation services. The survey also elicited responses regarding the level of needs for individual service items that could be delivered by nurses during home visits. The fieldwork was conducted by a consulting and research firm. The differences in whether respondents supported nurse home visitation services and intended to use nurse home visitation services according to mothers' characteristics were examined using the chi-square test. In total, 88.0% of survey participants supported nurse home visitation services, and 81.2% indicated that they intended to receive the services. Most pregnant women and women with children below the age of 24 months responded positively to the various prenatal or postpartum services that nurses could provide during home visits. The percentages of support for the services and intention to use services were generally high among subgroups according to mothers' characteristics. Therefore, universal home visitation services by nurses during pregnancy and in the postnatal period would be received well by Korean women.

Occupational inequalities in mortality in Korea: an analysis using nationally representative mortality follow-up data from the late 2000s and after.

Many Korean and international studies have found higher mortality rates and poorer health conditions among manual workers than among non-manual workers. However, a recent study using unlinked data argued that since the economic crisis in Korea in the late 2000s, the mortality estimates of male Korean non-manual workers have been higher than those of manual workers. Our work using individually linked data from the late 2000s and after aimed to examine mortality inequality by occupational class. We analyzed Korea National Health and Nutrition Examination Survey data that were individually linked to cause-of-death data. Cox regression analysis was used to identify the hazard ratios for mortality by occupational class. Of 11,766 males aged between 35 and 64, 397 died between 2007 and 2018: 142 died from cancer, 68 from cardiovascular disease, 88 from external causes, and 99 from other causes. After controlling for age, the mortality estimates for manual workers were 1.85 times higher than those for upper non-manual workers (p<0.05). We observed no evidence of reversed mortality inequality among occupational classes in Korea since the 2000s; this previously reported finding might have been due to numerator-denominator bias arising from the use of unlinked data.

Prevalence and risk factors of maternal depression among women who participated in a home visitation program in South Korea.

PURPOSE: The psychosocial health of mother is crucial for healthy prenatal period and early childhood. We investigated the prevalence and risk factors of maternal depression during pregnancy and postpartum among women who participated in a home visitation program in Seoul, South Korea (Seoul Healthy First Step Project, SHFSP). METHODS: We analyzed 80,116 women who participated in the SHFSP, which was launched by Seoul metropolitan government in 2013, and defined peripartum depression as a score ≥ 10 on the Korean version of the Edinburgh Postnatal Depression Scale (EPDS). Sociodemographic factors and psychosocial health status were evaluated through a standardized questionnaire completed by participants upon program registration. We calculated the prevalence of women at risk for peripartum depression and evaluated associated factors by multivariable logistic regression analysis. RESULTS: Prevalence of women at risk for peripartum depression was 17.7% (prepartum depression: 14.2%, postpartum depression: 24.3%). Younger maternal age, low income (OR 2.40, 95% CI 2.03-2.84), disability (2.61, 1.96-3.47), single parenthood (3.27, 2.69-3.99), and smoking (2.02, 1.44-2.83) increased the peripartum depression risk. Furthermore, experience of stress, change, or loss over the past 12 months (3.36, 3.22-3.50), history of treatment for emotional issues (2.47, 2.27-2.70), experience of child abuse (1.91, 1.74-2.11), and domestic violence (2.25, 1.81-2.80) increased the risk for peripartum depression, whereas having helpers for the baby (0.62, 0.58-0.67), having someone to talk with (0.31, 0.27-0.35), and considering oneself confident (0.30, 0.29-0.31) decreased the risk. CONCLUSIONS: Policies to reduce and manage peripartum depression should be strengthened, with a focus on high-risk pregnant and puerperal women.

Cancer-free Life Expectancy in Small Administrative Areas in Korea and Its Associations with Regional Health Insurance Premiums.

BACKGROUND: To determine the priorities and resource allocation of community cancer-related health policies, it is necessary to measure cancer-related health indicators and the burden of cancer by region. This study calculated the cancer-free life expectancy at the eup/myeon/dong level (small administrative units in South Korea) for the first time, and analyzed its association with regional health insurance premiums. METHODS: We used aggregate data from the 2008-2017 National Health Information Database provided by the National Health Insurance Service. Cancer-free life expectancy was calculated by applying Sullivan's method to mortality and cancer prevalence by age group and sex for the 10-year period in 3,396 eups/myeons/dongs. Correlation analyses were performed to analyze the relationship between cancer-free life expectancy and regional health insurance premiums. RESULTS: Cancer-free life expectancy in eups/myeons/dongs of metropolitan areas tended to be higher than in non-metropolitan areas. However, some eups/myeons/dongs of non-metropolitan areas showed quite a high cancer-free life expectancy, especially for females. The median values of differences between cancer-free life expectancy and life expectancy at the eup/myeon/dong level (total: 1.6 years, male: 1.8 years, female: 1.4 years) indicated that a person's healthy life can be shortened by a number of years due to cancer. The association of cancer-free life expectancy by eup/myeon/dong with the regional health insurance premium was statistically significant (ß = 1.0, P < 0.001) and more prominent for males (ß = 1.3, P < 0.001) than for females (ß = 0.5, P < 0.001). The relationship between the regional health insurance premium and the burden of cancer (life expectancy minus cancer-free life expectancy) was also statistically significant (ß = 0.2 for the total population, ß = 0.2 for males, and ß = 0.1 for females, all P values < 0.001). CONCLUSION: This study showed a significant regional gap with regard to cancer-free life expectancy and the burden of cancer at the eup/myeon/dong level. This work makes a meaningful contribution by presenting new and firsthand summary measures of cancer-related health across small areas in Korea. The results will also help the authorities to evaluate the effectiveness of local cancer management projects in small administrative areas and determine regional priorities for implementing cancer control policies.

Analysis of factors contributing to occupational health inequality in Korea: a cross-sectional study using nationally representative survey data.

BACKGROUND: Despite the consensus that higher occupational classes tend to have better health and lower mortality rates, one study has reported reversed occupational gradients in mortality rates among Korean men after the economic crisis in the late 2000s. To examine these patterns of health inequality in more detail, we investigated the tendency of occupational gradients in socioeconomic position and multiple pathway indicators known to affect mortality in Korea. METHODS: We used data from 4176 men aged 35-64 in Korea derived from the 2007-2009 and 2013-2015 Korean National Health and Nutrition Examination Surveys. We compared the age-standardized prevalence and age-adjusted mean values of each contributing factor to health inequality among occupational groups, which are divided into upper non-manual workers, lower non-manual workers, manual workers, and others. Contributing factors included childhood and adulthood socioeconomic position indicators, biological risk factors, health behaviors, psychosocial factors, and work environment. RESULTS: Upper non-manual workers had prominently higher levels of education, income, parental education, and economic activity than lower non-manual and manual workers. The rates of smoking and high-risk alcohol consumption were lower, and the rate of weight control activities was higher, in the non-manual classes. Further, the rates of depression and suicidal ideation were lower, and perceptions of the work environment were more favorable, among non-manual workers than among their manual counterparts. CONCLUSIONS: We detected occupational inequality in a wide range of socioeconomic positions and pathway indicators in Korea with consistently favorable patterns for upper non-manual workers. These occupational gradients do not support the previously reported reversed pattern of higher mortality rates in non-manual groups versus in the manual job class in Korea.

The Unequal Burden of Self-Reported Musculoskeletal Pains Among South Korean and European Employees Based on Age, Gender, and Employment Status.

BACKGROUND: The objective of this study was to elucidate the relationships musculoskeletal pains with combined vulnerability in terms of age, gender, and employment status. METHODS: The fifth European Working Conditions Survey (EWCS) in 2010 (43,816 participants aged 15 years and over) analyzed for European employees and the third Korean Working Conditions Survey (KWCS) in 2011 (50,032 participants aged 15 years and older) analyzed for Korean employees. In this study, three well known vulnerable factors to musculoskeletal pains (older age, female gender, and precarious employment status) were combined and defined as combined vulnerability. Associations of musculoskeletal pains with combined vulnerability were assessed with prevalence ratios (PRs) and 95% confidence intervals (CIs) estimated by Poisson regression models with robust estimates of variance. RESULTS: The prevalences of musculoskeletal pains were lower but the absolute and relative differences between combined vulnerabilities were higher among Korean employees compared with the European employees. Furthermore, the increased risk of having musculoskeletal pains according to combined vulnerability was modestly explained by socioeconomic factors and exposure to ergonomic risk factors, especially in Republic of Korea. CONCLUSIONS: The results of this study showed that the labor market may be more unfavorable for female and elderly workers in Republic of Korea. Any prevention strategies to ward off musculoskeletal pains, therefore, should be found and implemented to mitigate or buffer against the most vulnerable work population, older, female, and precarious employment status, in Republic of Korea.

Spatio-temporal Analysis of District-level Life Expectancy from 2004 to 2017 in Korea.

BACKGROUND: Health indicators, such as mortality rates or life expectancy, need to be presented at the local level to improve the health of local residents and to reduce health inequality across geographic areas. The aim of this study was to estimate life expectancy at the district level in Korea through a spatio-temporal analysis. METHODS: Spatio-temporal models were applied to the National Health Information Database of the National Health Insurance Service to estimate the mortality rates for 19 age groups in 250 districts from 2004 to 2017 by gender in Korea. Annual district-level life tables by gender were constructed using the estimated mortality rates, and then annual district-level life expectancy by gender was estimated using the life table method and the Kannisto-Thatcher method. The annual district-level life expectancies based on the spatio-temporal models were compared to the life expectancies calculated under the assumption that the mortality rates in these 250 districts are independent from one another. RESULTS: In 2017, district-level life expectancy at birth ranged from 75.5 years (95% credible interval [CI], 74.0-77.0 years) to 84.2 years (95% CI, 83.4-85.0 years) for men and from 83.9 years (95% CI, 83.2-84.6 years) to 88.2 years (95% CI, 87.3-89.1 years) for women. Between 2004 and 2017, district-level life expectancy at birth increased by 4.57 years (95% CI, 4.49-4.65 years) for men and by 4.06 years (95% CI, 3.99-4.12 years) for women. To obtain stable annual life expectancy estimates at the district level, it is recommended to use the life expectancy based on spatio-temporal models instead of calculating life expectancy using observed mortality. CONCLUSION: In this study, we estimated the annual district-level life expectancy from 2004 to 2017 in Korea by gender using a spatio-temporal model. Local governments could use annual district-level life expectancy estimates as a performance indicator of health policies to improve the health of local residents. The approach to district-level analysis with spatio-temporal modeling employed in this study could be used in future analyses to produce district-level health-related indicators in Korea.

Lessons learned and lessons missed: impact of the coronavirus disease 2019 (COVID-19) pandemic on all-cause mortality in 40 industrialised countries and US states prior to mass vaccination.

Background: Industrialised countries had varied responses to the coronavirus disease 2019 (COVID-19) pandemic, and how they adapted to new situations and knowledge since it began. These differences in preparedness and policy may lead to different death tolls from COVID-19 as well as other diseases. Methods: We applied an ensemble of 16 Bayesian probabilistic models to vital statistics data to estimate the impacts of the pandemic on weekly all-cause mortality for 40 industrialised countries from mid-February 2020 through mid-February 2021, before a large segment of the population was vaccinated in these countries. Results: Over the entire year, an estimated 1,410,300 (95% credible interval 1,267,600-1,579,200) more people died in these countries than would have been expected had the pandemic not happened. This is equivalent to 141 (127-158) additional deaths per 100,000 people and a 15% (14-17) increase in deaths in all these countries combined. In Iceland, Australia and New Zealand, mortality was lower than would be expected if the pandemic had not occurred, while South Korea and Norway experienced no detectable change in mortality. In contrast, the USA, Czechia, Slovakia and Poland experienced at least 20% higher mortality. There was substantial heterogeneity across countries in the dynamics of excess mortality. The first wave of the pandemic, from mid-February to the end of May 2020, accounted for over half of excess deaths in Scotland, Spain, England and Wales, Canada, Sweden, Belgium, the Netherlands and Cyprus. At the other extreme, the period between mid-September 2020 and mid-February 2021 accounted for over 90% of excess deaths in Bulgaria, Croatia, Czechia, Hungary, Latvia, Montenegro, Poland, Slovakia and Slovenia. Conclusions: Until the great majority of national and global populations have vaccine-acquired immunity, minimising the death toll of the pandemic from COVID-19 and other diseases will require actions to delay and contain infections and continue routine health care.

Stagnation of life expectancy in Korea in 2018: A cause-specific decomposition analysis.

According to the most recent annual report released by Korea Statistics, the life expectancy at birth (for both sexes) in 2018 was 82.7 years, an increase of 0.0 years over 2017, reflecting the first stagnation in life expectancy since 1960. In this study, a time-series analysis was conducted of trends in life expectancy from 2003 to 2018, and causes of death were analyzed using the Kannisto-Thatcher method and the Arriaga decomposition method. The time trend analysis of yearly life expectancy changes indicated that, in Korea, there was a tendency for the yearly increase in life expectancy between 2003 and 2018 to decrease by 0.0211 years per calendar year. The contribution of cardiovascular diseases, the most important contributor to the life expectancy increase in Korea, gradually decreased over this period. The contribution of cardiovascular diseases to the life expectancy increase was 0.506 years in 2003-2006, but this contribution decreased to 0.218 years in 2015-2018. The positive contributions of ill-defined causes and external causes to life expectancy increase detected in previous periods were not evident in 2015-2018. Diseases of the respiratory system made the largest negative contribution both between 2015 and 2018 and between 2017-2018. The life expectancy stagnation in 2018 could be understood as the combined effect of (a) decreasing momentum in the increase of life expectancy and (b) a chance event in 2018 involving life expectancy. Currently, it is difficult to judge whether the stagnation of life expectancy in 2018 is temporary, and further analyses of life expectancy and contributing causes of death in the future are needed.

Income differences in screening, incidence, postoperative complications, and mortality of thyroid cancer in South Korea: a national population-based time trend study.

BACKGROUND: The incidence of thyroid cancer (TC) has increased rapidly over the past few decades in Korea. This study investigated whether the TC epidemic has been driven by overdiagnosis. METHODS: We calculated the TC screening rate from mid-2008 through mid-2014, and the incidence, postoperative complication, and mortality rates of TC between 2006 and 2015, using data from the Korea Community Health Survey, the National Health Insurance Database, and the cause-of-death data of Statistics Korea. Trends in age-standardized rates of all indicators were examined, along with income gaps therein. Analyses were conducted for lung cancer and stroke as negative control outcomes. RESULTS: The incidence rate of TC increased from 46.6 per 100,000 to 115.0 per 100,000 between 2006 and 2012, and then decreased to 63.5 per 100,000 in 2015. Despite these remarkable changes in incidence, mortality did not fluctuate during the same period. High income was associated with high rates of screening, incidence, and postoperative complications, while low income showed an association with a high mortality rate. Analyses using negative control outcomes showed that high income was associated with low rates of both incidence and mortality, which contrasted with the patterns of TC. The recent decreases in TC incidence and postoperative complications, which reflect societal concerns about the overdiagnosis of TC, were more pronounced in high-income individuals than in low-income individuals. CONCLUSIONS: The time trends in income gaps in screening, incidence, postoperative complications, and mortality of TC, as well as negative control outcomes, provided corroborating evidence of TC overdiagnosis in Korea.

Age- and cause-specific contributions to the life expectancy gap between Medical Aid recipients and National Health Insurance beneficiaries in Korea, 2008-2017.

Recipients of Medical Aid, a government-funded social assistance program for the poor, have a shorter life expectancy than National Health Insurance beneficiaries in Korea. This study aims to explore the contributions of age and major causes of death to the life expectancy difference between the two groups. We used the National Health Information Database provided by the National Health Insurance Service individually linked to mortality registration data of Statistics Korea between 2008 and 2017. Annual abridged life tables were constructed and Arriaga's life expectancy decomposition method was employed to estimate age- and cause-specific contributions to the life expectancy gap between National Health Insurance beneficiaries and Medical Aid recipients. The life expectancy difference between National Health Insurance beneficiaries and Medical Aid recipients was 14.5 years during the period of 2008-2017. The age groups between 30 and 64 years accounted for 78.7% and 67.5% of the total life expectancy gap in men and women, respectively. Cancer was the leading cause of death contributing to excess mortality among Medical Aid recipients compared to National Health Insurance beneficiaries. More specifically, alcohol-attributable deaths (such as alcoholic liver disease, liver cancer, liver cirrhosis, and alcohol/substance abuse), suicide, and cardiometabolic risk factor-related deaths (such as cerebrovascular disease, ischemic heart disease, and diabetes) were the leading contributors to the life expectancy gap. To decrease excess deaths in Medical Aid recipients and reduce health inequalities, effective policies for tobacco and alcohol regulation, suicide prevention, and interventions to address cardiometabolic risk factors are needed.

Life Expectancy in Areas around Subway Stations in the Seoul Metropolitan Area in Korea, 2008-2017.

BACKGROUND: This study aimed to calculate life expectancy in the areas around 614 subway stations on 23 subway lines in the Seoul metropolitan area of Korea from 2008 to 2017. METHODS: We used the National Health Information Database provided by the National Health Insurance Service, which covers the whole population of Korea. The analysis was conducted on the level of the smallest administrative units within a 200-m radius of each subway station. Life expectancy was calculated by constructing an abridged life table using the number of population and deaths in each area and 5-year age groups (0, 1-4, …, 85+) during the whole study period. RESULTS: The median life expectancy in the areas around 614 subway stations was 82.9 years (interquartile range, 2.2 years; minimum, 77.6 years; maximum, 87.4 years). The life expectancy of areas around subway stations located in Seoul was higher than those in Incheon and Gyeonggi-do, but variation within the region was observed. Significant differences were observed between some adjacent subway stations. In Incheon and Gyeonggi-do, substantially higher life expectancy was found around subway stations in newly developed urban areas, and lower life expectancy was found in central Incheon and suburbs in Gyeonggi-do. CONCLUSION: When using areas around subway stations as the unit of analysis, variation in life expectancy in the Seoul metropolitan area was observed. This approach may reduce the stigma associated with presenting health inequalities at the level of the smallest administrative units and foster public awareness of health inequalities.

Comparison of three small-area mortality metrics according to urbanity in Korea: the standardized mortality ratio, comparative mortality figure, and life expectancy.

BACKGROUND: This study aimed to compare three small-area level mortality metrics according to urbanity in Korea: the standardized mortality ratio (SMR), comparative mortality figure (CMF), and life expectancy (LE) by urbanity. METHODS: We utilized the National Health Information Database to obtain annual small-area level age-specific numbers of population and deaths in Korea between 2013 and 2017. First, differences in the SMR by urbanity were examined, assuming the same age-specific mortality rates in all small areas. Second, we explored the differences in ranking obtained using the three metrics (SMR, CMF, and LE). Third, the ratio of CMF to SMR by population was analyzed according to urbanity. RESULTS: We found that the age-specific population distributions in urbanized areas were similar, but rural areas had a relatively old population structure. The age-specific mortality ratio also differed by urbanity. Assuming the same rate of age-specific mortality across all small areas, we found that comparable median values in all areas. However, areas with a high SMR showed a strong predominance of metropolitan areas. The ranking by SMR differed markedly from the rankings by CMF and LE, especially in areas of high mortality, while the latter two metrics did not differ notably. The ratio of CMF to SMR showed larger variations in small areas in rural areas, particularly in those with small populations, than in metropolitan and urban areas. CONCLUSIONS: In a comparison of multiple SMRs, bias could exist if the study areas have large differences in population structure. The use of CMF or LE should be considered for comparisons if it is possible to acquire age-specific mortality data for each small area.

Inequality in Life Expectancy in Korea according to Various Categorizations of the National Health Insurance Premiums as a Marker of Income.

The purpose of this study was to examine the degree to which the magnitude of income inequality in life expectancy according to different categorization across beneficiary types under the National Health Insurance Service (NHIS) in Korea. We used population and death data in 2017 from the National Health Information Database of the NHIS. Income quintile groups were classified in four ways according to beneficiary type (employee insured, self-employed insured, and Medical Aid beneficiaries). Standard life table procedures were used to calculate life expectancy. The life expectancy gap between the lowest and highest income quintiles was the largest when the entire population was divided into quintiles without distinguishing among types of beneficiaries. In conclusion, we suggest that income quintile indicators in NHIS data, measured without distinguishing among types of beneficiaries, may best represent the magnitude of health inequalities in Korean society. This indicator could be used for future research on health inequalities, as well as for monitoring health inequalities in Korea.

Mediation effect of herpes zoster derived by statin use on cardiovascular disease risk.

BACKGROUND/AIMS: Although statins are widely used to reduce the risk of cardiovascular disease (CVD) including stroke and myocardial infarction (MI), it is reported that statin use increases the incidence of herpes zoster (HZ) that is associated with increased risk of CVD. So, we evaluated the mediation effect of HZ caused by statin use on CVD. METHODS: We analyzed a prospective cohort from the National Health Insurance Service-database of South Korea. All individuals received a medical check-up and were followed-up from 2002 to 2013. RESULTS: A total of 275,382 individuals > 40 years old were followed up for 11 years from 2003. Of these, 11,415 people (4%) were classified as statin users and 263,967 (96%) as non-statin users. Those who used statins had significantly lower risks of cardiovascular events, stroke, and MI compared with non-statin users; the adjusted hazard ratios in the multivariate analysis were 0.90 (95% confidence interval [CI], 0.82 to 0.98), 0.88 (95% CI, 0.80 to 0.98), and 0.91 (95% CI, 0.79 to 1.07), respectively. When we calculated the mediating effect of cardiovascular events by statin use through HZ, 11.6% of the total beneficial effect of cardiovascular events by statin use was mitigated through the occurrence of HZ caused by statin use. This mediating effect was higher in the younger age group (< 60 years). CONCLUSION: This study showed that statin use reduced CVD by 10%, but the protective effect of statin use against CVD was mitigated by approximately 10% through the development of HZ caused by statin use.