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 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.

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.

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.

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.

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.

Income-related inequality in quality-adjusted life expectancy in Korea at the national and district levels.

BACKGROUND: The aim of this study was to measure differences in quality-adjusted life expectancy (QALE) by income in Korea at the national and district levels. METHODS: Mortality rates and EuroQol-5D (EQ-5D) scores were obtained from the National Health Information Database of the National Health Insurance Service and the Korea Community Health Survey, respectively. QALE and differences in QALE among income quintiles were calculated using combined 2008-2014 data for 245 districts in Korea. Correlation analyses were conducted to investigate the associations of neighborhood characteristics with QALE and income gaps therein. RESULTS: QALE showed a graded pattern of inequality according to income, and increased over time for all levels of income and in both sexes, except for low-income quintiles among women, resulting in a widened inequality in QALE among women. In all 245 districts, pro-rich inequalities in QALE were found in both men and women. Districts with higher QALE and smaller income gaps in QALE were concentrated in metropolitan areas, while districts with lower QALE and larger income gaps in QALE were found in rural areas. QALE and differences in QALE by income showed relatively close correlations with socioeconomic characteristics, but relatively weak correlations with health behaviors, except for smoking and indicators related to medical resources. CONCLUSIONS: This study provides evidence of income-based inequalities in health measured by QALE in all subnational areas in Korea. Furthermore, QALE and differences in QALE by income were closely associated with neighborhood-level socioeconomic characteristics.

Tobacco price increases in Korea and their impact on socioeconomic inequalities in smoking and subsequent socioeconomic inequalities in mortality: a modelling study.

OBJECTIVE: Through a modelling study, we assessed the impact of tobacco price increases on smoking and smoking inequalities by income, and then quantified the subsequent effects on mortality and inequalities in mortality in Korea. METHODS: Eleven-year pooled data from the Korea National Health and Nutrition Examination Survey (KNHANES) (n=65 197) were used to estimate the income group-specific price elasticity. The price elasticity was then used to calculate changes in current smoking prevalence and per capita cigarette consumption resulting from a spectrum of hypothetical tobacco price increases. The mortality risk function from the 10-year mortality follow-up data of the National Health Insurance Service-National Sample Cohort (n=293 858, numbers of deaths=14 953) and the current distributions of smoking-related variables from the KNHANES 2015-2017 were employed to estimate the effect of tobacco price increases on inequality in mortality. RESULTS: Low-income Korean smokers were more responsive to changes in tobacco price. Increasing the tobacco price by 100% would achieve the overall reduction of 2.0% for 10-year mortality. For mortality inequalities by income, the relative index of inequality (slope index of inequality) would be reduced by 3.8% (4.8%) for 10-year mortality. CONCLUSIONS: This modelling study showed that tobacco price increases in Korea can reduce current smoking prevalence and per capita cigarette consumption in the whole population, and especially among the poor, which in turn would reduce the gap in mortality between income groups.

Inequalities in Longitudinal Health Trajectories in Middle to Later Life: a Comparison of European Countries and Korea.

BACKGROUND: This study compared inequalities in the longitudinal trajectory of health measured by latent growth curves (LGCs) in Korea and six other developed European countries. METHODS: Unconditional and conditional LGCs were fitted, with standardized self-rated health (SRH) as the outcome variable. Two nationally-representative longitudinal datasets were used: the Survey of Health, Aging and Retirement in Europe (2007-2015; 2,761 Swedish, 2,546 Danish, 2,580 German, 2,860 French, 2,372 Spanish, and 2,924 Italian respondents) and the Korean Longitudinal Study of Aging (2006-2014; 8,465 Korean respondents). RESULTS: The unconditional patterns of SRH trajectory were similar and unfavorable for women across the countries. Social factors such as education and income generally exerted a significant impact on health trends among older adults. Korea showed less favorable results for the disadvantaged than the advantaged as compared with Denmark, Germany, and France, which was consistent with theoretical expectations. In contrast, the relative SRH trajectory of the disadvantaged as against the advantaged was better as compared with Sweden and worse as compared with Spain/Italy, which was inconsistent with theories that would predict Korea's results were worse than Sweden and similar to Spain/Italy. Women had good SRH trajectory in Denmark and poorer SRH trajectory in Spain, Italy, and Korea, which were consistent. However, women in Sweden showed poorer and mixed outcome, which does not correspond to theoretical predictions. CONCLUSION: These findings suggest that it is inconclusive whether Sweden and Denmark (with the most generous welfare arrangements) have better trajectories of health, and Spain, Italy, and Korea (with the least advanced state policies) have worse SRH paths among older adults. However, it can be inferred that Korean governmental policies may have produced a relatively worse context for the less-educated than the six European countries, as well as poorer settings for women than Denmark in terms of their initial SRH status.

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.

Long-term trends in smoking prevalence and its socioeconomic inequalities in Korea, 1992-2016.

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.

Trends in life expectancy among medical aid beneficiaries and National Health Insurance beneficiaries in Korea between 2004 and 2017.

BACKGROUND: Medical Aid beneficiaries in Korea are more likely to have poor health status and to receive insufficient healthcare services, but their life expectancy has not been compared with that of National Health Insurance beneficiaries. METHODS: We used the National Health Information Database in Korea to obtain aggregate data on the numbers of population and deaths according to calendar year (2004 to 2017), sex, age group, and insurance eligibility (Medical Aid or National Health Insurance). Between 2004 and 2017, a summed total of 697,503,634 subjects (combining numbers of subjects for 14 years) and 3,536,778 deaths, including 22,417,216 Medical Aid beneficiaries and 499,604 associated deaths, were used to construct annual abridged life tables. RESULTS: In 2017, the life expectancy of Medical Aid beneficiaries was 70.9 years, while that of National Health Insurance beneficiaries was 83.7 years. Between 2004 and 2017, life expectancy for Medical Aid beneficiaries increased by 8.7 years in men and 6.1 years in women, while life expectancy for National Health Insurance beneficiaries increased by 5.2 years in men and 4.5 years in women. The life expectancy difference between National Health Insurance beneficiaries and Medical Aid beneficiaries was especially great among men across all study periods. The life expectancy difference was 15.8 years for men and 8.9 years for women in 2017. CONCLUSIONS: The life expectancy of Medical Aid beneficiaries was shorter than that of National Health Insurance beneficiaries. The government should implement policies to deliver more adequate health care to Medical Aid beneficiaries.

Use of the National Health Information Database for Estimating Town-Level Mortality in Korea: Comparison with the National Administrative Data, 2014-2017.

BACKGROUND: This study addressed town-level mortality rates using the National Health Information Database (NHID) of the National Health Insurance Service in Korea in comparison with those derived from the National Administrative Data (NAD) of the Ministry of Interior and Safety. METHODS: We employed the NHID and NAD between 2014 and 2017. We compared the numbers of population and deaths at the national level between these two data sets. We also compared the distribution of the town-level numbers of population and deaths of the two data sets. Correlation analyses were performed to investigate the relation between the NHID and NAD in the town-level numbers of population and deaths, crude mortality rate, and standardized mortality ratio (SMR). RESULTS: The numbers of population and deaths in the NHID were almost identical to those in the NAD, regardless of gender. The distribution of the town-level numbers of population and deaths was also similar between the two data sets during the entire study period. Throughout the study period, the Pearson correlation coefficients between the two databases for the town-level numbers of population and deaths and the crude mortality rate were 0.996 or over. The correlation coefficients for the SMR ranged from 0.937 to 0.972. CONCLUSION: Town-level mortality showed significant correlation and concordance between the NHID and NAD. This result highlights the possibility of producing future analyses of town-level health-related indicators in Korea, including the mortality rate, using the NHID.

Prevalence and risk factors of elevated alanine aminotransferase among Korean adolescents: 2001-2014.

BACKGROUND: An elevated alanine aminotransferase (ALT) level is a surrogate marker of non-alcoholic fatty liver disease (NAFLD), the most common liver disorder in adolescents. The majority of previous NAFLD studies in adolescents were performed in selected obese populations or had a cross-sectional design without a time-trend analysis. The purpose of this study was to estimate the prevalence and time trends of elevated ALT levels in a general adolescent population and to identify factors associated with ALT elevation. METHODS: We analysed data of adolescent participants (aged 10-18 years) from the Korean National Health and Nutrition Examination Survey 2001-2014, a representative sample of the general population in South Korea. Suspected NAFLD was defined as ALT elevation (> 30 U/L) without hepatitis B surface antigen. In all statistical analyses, sampling weight- and design-based data were used. RESULTS: ALT was elevated in 5.3% (standard error: 0.3%) of the study population of adolescent participants (N = 8455). No significant trends were found from 2001 to 2014 in the prevalence of elevated ALT among male and female adolescents. In multiple logistic regression analysis, elevated ALT was independently associated with sex (odds ratio [OR] male versus female 4.5; 95% CI, 3.3-6.2), obesity (OR 7.6; 95% CI, 5.3-11.0), and truncal obesity (OR 2.5; 95% CI, 1.8-3.5). Furthermore, male sex, obesity, truncal obesity and high household income level were associated with log-transformed ALT levels in multiple regression analysis. CONCLUSIONS: In Korean adolescents of both genders, the prevalence of elevated ALT levels was stable from 2001 to 2014. This study has revealed that sex, obesity, truncal obesity and household income level are associated with ALT elevation in adolescents.

The life expectancy gap between North and South Korea from 1993 to 2008.

Background: Comparative research on health outcomes in North and South Korea offers a unique opportunity to explore political and social determinants of health. We examined the age- and cause-specific contributions to the life expectancy (LE) gap between the two Koreas. Methods: We calculated the LE at birth in 1993 and 2008 among North and South Koreans, and cause-specific contributions to the LE discrepancy between the two Koreas in 2008. The cause-specific mortality data from South Korea were used as proxies for the cause-specific mortality data in North Korea in 2008. Results: The LE gap between the two Koreas was approximately 1 year in 1993, but grew to approximately 10 years in 2008. This discrepancy was attributable to increased gaps in mortality among children younger than 1 year and adults 55 years of age or older. The major causes of the increased LE gap were circulatory diseases, digestive diseases, infant mortality, external causes, cancers and infectious diseases. Conclusions: This study underscores the urgency of South Korean and international humanitarian aid programs to reduce the mortality rate of the North Korean people.

Association between Dental Caries and Delayed Growth in Korean Children.

The purpose of this study was to assess the relationship of dental caries with anthropometric outcomes in 4- to 6-year-old children participating in the Korean National Health and Nutrition Examination Survey (KNHANES). The sample size was 1,910 children from the 4th and 5th KNHANES. The caries status was assessed with the decayed and filled teeth index in primary dentition (dft score). We employed height for age, body weight for age, and body mass index for age as outcome variables. Age, gender, region, and income were confounders. Nutritional deficiency as a mediator in the association between dental caries and delayed growth was also examined. A series of logistic regression analyses estimated the magnitude of association between dental caries and unfavorable growth after adjustment of the confounders and the mediator. Those with a high dft score were more likely to be deficient in nutrition (OR 1.77, 95% CI 1.14-2.74). After adjusting for sociodemographic factors and nutritional deficiency, we also found that a high dft score was associated with low weight (OR 1.70, 95% CI 1.15-2.51). The influence of dental caries on delayed growth was found in Korean representative children.

Comparison of District-level Smoking Prevalence and Their Income Gaps from Two National Databases: the National Health Screening Database and the Community Health Survey in Korea, 2009-2014.

BACKGROUND: We compared age-standardized prevalence of cigarette smoking and their income gaps at the district-level in Korea using the National Health Screening Database (NHSD) and the Community Health Survey (CHS). METHODS: Between 2009 and 2014, 39,049,485 subjects participating in the NHSD and 989,292 participants in the CHS were analyzed. The age-standardized prevalence of smoking and their interquintile income differences were calculated for 245 districts of Korea. We examined between-period correlations for the age-standardized smoking prevalence at the district-level and investigated the district-level differences in smoking prevalence and income gaps between the two databases. RESULTS: The between-period correlation coefficients of smoking prevalence for both genders were 0.92-0.97 in NHSD and 0.58-0.69 in CHS, respectively. When using NHSD, we found significant income gaps in all districts for men and 244 districts for women. However, when CHS was analyzed, only 167 and 173 districts for men and women, respectively, showed significant income gaps. While correlation coefficients of district-level smoking prevalence from two databases were 0.87 for men and 0.85 for women, a relatively weak correlation between income gaps from the two databases was found. CONCLUSION: Based on two databases, income gaps in smoking prevalence were evident for nearly all districts of Korea. Because of the large sample size for each district, NHSD may provide stable district-level smoking prevalence and its income gap and thus should be considered as a valuable data source for monitoring district-level smoking prevalence and its socioeconomic inequality.

Prevalence of Overweight and Income Gaps in 245 Districts of Korea: Comparison Using the National Health Screening Database and the Community Health Survey, 2009-2014.

BACKGROUND: We compared age-standardized overweight prevalence and their income gaps at the level of district in Korea using the National Health Screening Database (NHSD) and the Community Health Survey (CHS). METHODS: We analyzed 39,093,653 subjects in the NHSD and 926,580 individuals in the CHS between 2009 and 2014. For the comparison of body mass index (BMI) distributions, data from 26,100 subjects in the Korea National Health and Nutrition Examination Survey (KNHANES) were also analyzed. We calculated the age-standardized overweight prevalence and its interquintile income gap at the district level. We examined the magnitudes of the between-period correlation for age-standardized overweight prevalence. The differences in overweight prevalence and its income gap between the NHSD and the CHS were also investigated. RESULTS: The age-adjusted mean BMI from the CHS was lower than those from the NHSD and the KNHANES. The magnitudes of the between-period correlation for overweight prevalence were greater in the NHSD compared to the CHS. We found that the district-level overweight prevalence in the NHSD were higher in all districts of Korea than in the CHS. The correlation coefficients for income gaps in overweight prevalence between the two databases were relatively low. In addition, when using the NHSD, the district-level income inequalities in overweight were clearer especially among women than the inequalities using the CHS. CONCLUSION: The relatively large sample size for each district and measured anthropometric data in the NHSD are more likely to contribute to valid and reliable measurement of overweight inequality at the district level in Korea.

Global Cardiovascular and Renal Outcomes of Reduced GFR.

The burden of premature death and health loss from ESRD is well described. Less is known regarding the burden of cardiovascular disease attributable to reduced GFR. We estimated the prevalence of reduced GFR categories 3, 4, and 5 (not on RRT) for 188 countries at six time points from 1990 to 2013. Relative risks of cardiovascular outcomes by three categories of reduced GFR were calculated by pooled random effects meta-analysis. Results are presented as deaths for outcomes of cardiovascular disease and ESRD and as disability-adjusted life years for outcomes of cardiovascular disease, GFR categories 3, 4, and 5, and ESRD. In 2013, reduced GFR was associated with 4% of deaths worldwide, or 2.2 million deaths (95% uncertainty interval [95% UI], 2.0 to 2.4 million). More than half of these attributable deaths were cardiovascular deaths (1.2 million; 95% UI, 1.1 to 1.4 million), whereas 0.96 million (95% UI, 0.81 to 1.0 million) were ESRD-related deaths. Compared with metabolic risk factors, reduced GFR ranked below high systolic BP, high body mass index, and high fasting plasma glucose, and similarly with high total cholesterol as a risk factor for disability-adjusted life years in both developed and developing world regions. In conclusion, by 2013, cardiovascular deaths attributed to reduced GFR outnumbered ESRD deaths throughout the world. Studies are needed to evaluate the benefit of early detection of CKD and treatment to decrease these deaths.

Geographic Variation in Morbidity and Mortality of Cerebrovascular Diseases in Korea during 2011-2015.

BACKGROUND: Little is known about within-country variation in morbidity and mortality of cerebrovascular diseases (CVDs). Geographic differences in CVD morbidity and mortality have yet to be properly examined. This study examined geographic variation in morbidity and mortality of CVD, neighborhood factors for CVD morbidity and mortality, and the association between CVD morbidity and mortality across the 245 local districts in Korea during 2011-2015. METHODS: District-level health care utilization and mortality data were obtained to estimate age-standardized CVD morbidity and mortality. The bivariate Pearson correlation was used to examine the linear relationship between district-level CVD morbidity and mortality Z-scores. Simple linear regression and multivariate analyses were conducted to investigate the associations of area characteristics with CVD morbidity, mortality, and discrepancies between morbidity and mortality. RESULTS: Substantial variation was found in CVD morbidity and mortality across the country, with 1074.9 excess CVD inpatients and 73.8 excess CVD deaths per 100,000 between the districts with the lowest and highest CVD morbidity and mortality, respectively. Higher rates of CVD admissions and deaths were clustered in the noncapital regions. A moderate geographic correlation between CVD morbidity and mortality was found (Pearson correlation coefficient = .62 for both genders). Neighborhood level indicators for socioeconomic disadvantages, undersupply of health care resources, and unhealthy behaviors were positively associated with CVD morbidity and mortality and the relative standing of CVD mortality vis-à-vis morbidity. CONCLUSIONS: Policy actions targeting life-course socioeconomic conditions, equitable distribution of health care resources, and behavioral risk factors may help reduce geographic differences in CVD morbidity and mortality in Korea.