The relative importance of macro versus micro geographical scale in explaining suicide variation in Seoul, South Korea 2014-2016.

BACKGROUND: As ecological factors are getting attention as important determinants of suicide, it is important to identify the unit at which the largest variation exists for more tailed strategy to prevent suicide. We examined the relative importance of two administrative levels for geographic variation in the suicide rate between 2014-2016 in Seoul, the capital city of Korea. METHODS: Two-level linear regression with Dongs (level 1) nested within Gus (level 2) was performed based on suicide death data aggregated at the Dong-level. We performed pooled analyses and then year-stratified analyses. Dong-level socioeconomic status and environmental characteristics were included as control variables. RESULTS: The overall age- and sex- standardized suicide rate across all Dongs decreased over time from 24.9 deaths per 100,000 in 2014 to 23.7 deaths in 2016. When Dong and Gu units were simultaneously considered in a multilevel analysis, most of the variation in suicide rate was attributed to within-Gu, between-Dong differences with a contribution of Gu-level being small and decreasing over time in year (Variance partitioning coefficient of Gu = 5.3% in 2014, <0.1% in 2015 and 2016). The number of divorce cases per 100,000 explained a large fraction of variation in suicide rate at the Dong-level. CONCLUSIONS: Findings from this study suggest that ecological micro-area unit is more important in reducing the geographic variation in the suicide rate. More diverse ecological-level data needs to be collected for targeted area-based suicide prevention policies in Korea.

Income-Related Mortality Inequalities and Its Social Factors among Middle-Aged and Older Adults at the District Level in Aging Seoul: An Ecological Study Using Administrative Big Data.

This study investigated income-related health inequality at sub-national level, focusing on mortality inequality among middle-aged and older adults (MOAs). Specifically, we examined income-related mortality inequality and its social factors among MOAs across 25 districts in Seoul using administrative big data from the National Health Insurance Service (NHIS). We obtained access to the NHIS's full-population micro-data on both incomes and demographic variables for the entire residents of Seoul. Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were calculated. The effects of social attributes of districts on SIIs and RIIs were examined through ordinary least squares and spatial regressions. There were clear income-related mortality gradients. Cross-district variance of mortality rates was greater among the lowest income group. SIIs were smaller in wealthier districts. Weak spatial correlation was found in SIIs among men. Lower RIIs were linked to lower Gini coefficients of income for both genders. SIIs (men) were associated with higher proportions of special occupational pensioners and working population. Lower SIIs and RIIs (women) were associated with higher proportions of female household heads. The results suggest that increasing economic activities, targeting households with female heads, reforming public pensions, and reducing income inequality among MOAs can be good policy directions.

Changes of hospitalization trend in the pediatric cardiology division of a single center by increasing adult with congenital heart disease.

BACKGROUND: As a result of advances in pediatric care and diagnostic testing, there is a growing population of adults with congenital heart disease (ACHD). The purpose of this study was to better define the epidemiology and changes in the trend of hospitalizations for ACHD in Korean society. METHODS: We reviewed outpatient and inpatient data from 2005 to 2017 to identify patient ≥18 years of age admitted for acute care with a congenital heart disease (CHD) diagnosis in the pediatric cardiology division. We tried to analyze changes of hospitalization trend for ACHD. RESULTS: The ratio of outpatients with ACHD increased 286.5%, from 11.1% (1748/15,682) in 2005 to 31.8% (7795/24,532) in 2017. The number of ACHD hospitalizations increased 360.7%, from 8.9% (37/414) in 2005 to 32.1% (226/705) in 2017. The average patient age increased from 24.3 years in 2005 to 27.4 in 2017. The main diagnosis for admission of ACHD is heart failure, arrhythmia and Fontan-related complications. The annual ICU admission percentage was around 5% and mean length of intensive care unit (ICU) stay was 8.4 ± 14.6 days. Mean personal hospital charges by admission of ACHD increased to around two times from 2005 to 2017. (from $2578.1 to $3697.0). Total annual hospital charges by ACHD markedly increased ten times (from $95,389.7 to $831,834.2). CONCLUSIONS: The number of hospital cares for ACHD dramatically increased more than five times from 2005 to 2017. We need preparations for efficient healthcare for adults with CHD such as a multi-dimensional approach, effective communication, and professional training.

Analysis of accessibility to emergency rooms by dynamic population from mobile phone data: Geography of social inequity in South Korea.

Accessibility of emergency medical care is one of the crucial factors in evaluating national primary medical care systems. While many studies have focused on this issue, there was a fundamental limit to the measurement of accessibility of emergency rooms, because the commonly used census-based population data are difficult to provide realistic information in terms of time and space. In this study, we evaluated the geographical accessibility of emergency rooms in South Korea by using dynamic population counts from mobile phone data. Such population counts were more accurate and up-to-date because they are obtained by aggregating the number of mobile phone users in a 50-by-50 m grid of a locational field, weighted by stay time. Considering both supply and demand of emergency rooms, the 2-step floating catchment analysis was implemented. As a result, urban areas, including the capital city Seoul, showed lower accessibility to emergency rooms, whereas rural areas recorded higher accessibility. This result was contrary to the results analyzed by us based on census-based population data: higher accessibility in urban areas and lower in rural. This implies that using solely census data for accessibility analysis could lead to certain errors, and adopting mobile-based population data would represent the real-world situations for solving problems of social inequity in primary medical care.

Not all cicadas increase thermal tolerance in response to a temperature gradient in metropolitan Seoul.

Rapid anthropogenic alterations caused by urbanization are increasing temperatures in urban cores, a phenomenon known as the urban heat island (UHI) effect. Two cicada species, Cryptotympana atrata and Hyalessa fuscata (Hemiptera: Cicadidae), are abundant in metropolitan Seoul where their population densities correlate strongly with UHI intensities. Such a positive correlation between cicada density and UHI intensity may be possible if cicada abundance is linked to a certain thermal tolerance. We tested this hypothesis by investigating variation in morphology and thermal responses of two cicada species along a thermal gradient in Seoul and surrounding areas. The morphological responses were measured by metrics such as length, thorax width and depth, and mass. The thermal responses were measured in terms of minimum flight temperature, maximum voluntary temperature and heat torpor temperature. First, we observed a species-specific variation in thermal responses, in which C. atrata displayed a higher thermal threshold for maximum voluntary and heat torpor temperatures than H. fuscata. Second, a positive association between temperature conditions and body sizes were displayed in females H. fuscata, but not in either conspecific males or C. atrata individuals. Third, C. atrata exhibited similar thermal responses regardless of habitat temperature, while H. fuscata in warmer areas showed an increase in heat tolerance. In addition, H. fuscata individuals with bigger thorax sizes were more heat-tolerant than those with smaller thoraxes. Overall, our research is the first to detect a variation in thermal responses and body size of H. fuscata individuals at a local scale. More investigations would be needed to better understand the adaptation mechanisms of insects linked to UHI effects.

Associations Among Health Insurance Type, Cardiovascular Risk Factors, and the Risk of Dementia: A Prospective Cohort Study in Korea.

Due to an aging population, dementia incidence has rapidly increased in South Korea, heaping psychological and economic burdens upon families and the society. This study was aimed at investigating the associations of health insurance type and cardiovascular risk factors with the risk of dementia. The study was performed using data from 15,043 participants aged 60 years and above, enrolled in the Seoul Dementia Management Project in 2008 and followed up until 2012. Factors such as demographic data, health insurance type, lifestyle factors, and cardiovascular risk factors were subjected to Cox proportional hazard regression analysis to identify their associations with dementia incidence. During the follow-up, 495 participants (3.3%) developed dementia. Medical Aid beneficiaries were associated with an increase in the risk of dementia (hazard ratio [HR] 1.77, 95% confidence interval [CI] 1.421-2.215). Upon analyzing a composite cardiovascular risk score derived from all five cardiovascular risk factors, the risk for dementia incidence in participants increased from 1.56 for the presence of three risk factors to 2.55 for that of four risk factors (HR 2.55, 95% CI 1.174-5.546), compared with those who had no risk factors. The Medical Aid beneficiaries of health insurance type and the presence of multiple cardiovascular risk factors were found to be associated with a higher risk of dementia incidence.

Educational Disparities in Risk for Metabolic Syndrome.

BACKGROUND: The objective of this study was to evaluate the relationship between educational level as a surrogate marker of socioeconomic status and the risk of developing metabolic syndrome (MetS). METHODS: Study subjects were 1915 Korean adults (1193 women and 722 men) who participated in a cohort study. Educational level was categorized into two groups: (1) high education (more than 12 years of education), and (2) low education (less than 12 years of education). MetS was defined according to diagnostic criteria of the National Cholesterol Education Program (NCEP-III) and the International Diabetes Federation (IDF). Multiple logistic regression analysis and Cox proportional hazard analysis were performed to evaluate cross-sectional and prospective association between MetS or MetS components and educational level after adjusting for covariates. RESULTS: The overall prevalence of MetS at baseline was 15.0% in women and 20.4% in men. Incidence of MetS over 4.52 years was 16.6 per 1000 person-year in women and 27.6 per 1000 person-year in men. The prevalence and incidence of MetS were higher in the low educational group than those in the high educational group in both sexes. At baseline, the risk of MetS (odds ratio [OR]: 1.63, 95% confidence interval [CI]: 1.05-2.53 for NCEP criteria; OR: 2.30, 95% CI: 1.41-3.76 for IDF criteria) and abdominal obesity (OR: 2.62, 95% CI: 1.75-3.93) were higher in less educated women compared with those in more educated women. In men, there was no association between Mets or MetS components and educational level. Over 4.6 years of follow-up, the risk of developing MetS in women in the low education group (hazard ratio [HR]: 1.95, 95% CI: 1.12-3.50 for NCEP criteria; HR: 2.36, 95% CI: 1.14-4.86 for IDF criteria) was significantly higher than that in the high education group. In men, low education significantly increased the risk of developing impaired fasting glucose (HR: 1.95, 95% CI: 1.12-3.40). CONCLUSION: An inverse association between educational level and MetS was found in Korean women, suggesting that socioeconomic disparities might increase the risk of MetS development, especially in women.

Factors associated with secondhand smoke incursion into the homes of non-smoking residents in a multi-unit housing complex: a cross-sectional study in Seoul, Korea.

BACKGROUND: In a multi-unit housing (MUH) complex, secondhand smoke (SHS) can pass from one living space to another. The aim of this study was to determine the prevalence of SHS incursion, and to establish the relationship between SHS incursion and socio-demographic and built environmental factors in MUH in Korea. METHODS: A population-based sample of 2600 residents (aged ≥19 years) living in MUH from across the city of Seoul, Korea, was obtained through a web-based selection panel. The residents completed a questionnaire detailing socio-demographic factors, smoking status, frequency of SHS incursion, and built environmental factors. The presence of a personal smoke-free home rule was determined by residents declaring that no one smoked inside the home. RESULTS: Of the 2600 participants, non-smoking residents who lived in homes with a personal smoke-free rule were selected for further analysis (n = 1784). In the previous 12 months, 74.7% of residents had experienced SHS incursion ≥1 times. A multivariate ordinal logistic regression analysis indicated that residents who spent more time at home, lived with children, supported the implementation of smoke-free regulations in MUH, lived in small homes, lived in homes with natural ventilation provided by opening a front door or the windows and front door, and lived in homes with more frequent natural ventilation were more likely to report SHS incursion into their homes. CONCLUSIONS: The majority of the non-smoking residents experienced SHS incursion, even with a personal smoke-free rule in their homes. A smoke-free policy in MUH is needed to protect residents from SHS exposure when they are at home.

Effect of Individual and District-level Socioeconomic Disparities on Cognitive Decline in Community-dwelling Elderly in Seoul.

This study was to investigate the effects of individual and district-level socioeconomic status (SES) on the development of cognitive impairment among the elderly. A 3-year retrospective observational analysis (2010-2013) was conducted which included 136,217 community-dwelling healthy elderly who participated in the Seoul Dementia Management Project. Cognitive impairment was defined as 1.5 standard deviations below the norms on the Mini-mental status examination. In the individual lower SES group, the cumulative incidence rate (CIR) of cognitive impairment was 8.7% (95% confidence interval [CI], 8.64-8.70), whereas the CIR in the individual higher SES group was 4.1% (95% CI, 4.08-4.10). The CIR for lower district-level SES was 4.7% (95% CI, 4.52-4.86), while that in the higher district-level SES was 4.3% (95% CI, 4.06-4.44). There were no additive or synergistic effects between individual and district-level SES. From this study, the individual SES contributed 1.9 times greater to the development of cognitive impairment than the district-level SES, which suggests that individual SES disparities could be considered as one of the important factors in public health related to cognitive impairment in the elderly.

Community socioeconomic status and public access defibrillators: A multilevel analysis.

BACKGROUND: Although current guidelines recommend that distribution of public-access defibrillators (PADs) should take into account area-level risk of out-of-hospital cardiac arrest (OHCA), community socioeconomic status (SES) can unduly influence policy implementation in positioning PADs. Using recent, complete data from Seoul Metropolitan City, Korea, this study aims to examine whether community SES is associated with distribution of PADs, in terms of per capita count and risk-grid coverage. METHODS: A cross-sectional, observational study was conducted using three sources of administrative data: (1) PAD registry data (2007-2015), (2) OHCA database (2010-2014), and (3) community socioeconomic characteristics of two sub-city levels (neighborhoods nested in districts). We examined the relationship between neighborhood per capita tax, an SES proxy, with each of the two outcome variables. After examining per capita number of PADs and risk-grid coverage by neighborhood tax quartile, multilevel linear regression analysis was conducted to account for the nested nature of data and also to control for OHCA risk in the model. RESULTS: A total of 6609 PADs in 405 neighborhoods were included in the analysis. The average number of positioned PADs per 10,000 persons was 7.45, showing a gradient by neighborhood SES (4.92 in the lowest SES quartile vs 12.66 in the highest). Risk-grid coverage was around 10% across all neighborhood SES quartiles. These findings remained valid in the multilevel analysis: per capita number of PADs was still positively associated with neighborhood SES, while risk-grid coverage of PADs was not. CONCLUSIONS: More affluent neighborhoods in Seoul exhibit higher per capita PADs, even accounting for OHCA risk, while risk-grid coverage is generally low regardless of community SES. Seoul's ongoing program aimed to increase PAD coverage should also pay attention to improving community-level inequality as well as distributional efficiency.

Assessment of temporal variation for the risk of particulate matters on asthma hospitalization.

Increased ambient concentration of particulate matters are considered as one of major causes for increased prevalence or exacerbation of asthma or asthma like symptoms. Recently, possible temporal variation in risks of PM on mortality has been suggested. We investigated short-term effect of both PM10 and PM2.5 on asthma hospitalization, and assessed temporal variation of PM risks in Seoul, Korea, 2003-2011. Generalized additive model was used to estimate PM risks on asthma hospitalization with consideration by long-term trend, influenza epidemic, day of week, meteorological factors. To assess temporal variation of PM risks, year-round PM risks were estimated. Stratified analysis by season and age-group were also conducted. Estimated RRs of PM on asthma hospitalization by an increase of 10㎍/㎥were 1.0084 (95% CI: 1.0041-1.0127) and 1.0156 (95% CI: 1.0055-1.0259) respectively with 7-days lag periods (lag06). PM2.5 had stronger effect than PM10 for all age group. Elderly group was most affected by PM. For the analysis of temporal variation of PM risks, we found increasing trend in total population and the elderly group. In the season-specific analysis, we also found increasing trend in winter for PM10, and in spring for PM2.5. PM10 and PM2.5 has adverse effect on asthma hospitalization with evidence suggesting temporal variation in PM risks. Further research will be needed to confirm the temporal variation of PM risk on asthma hospitalization, and to identify casual factors affecting this temporal variation. This study results could be evidentiary materials for establishing valid public health policies to reduce health burden or economic burden of asthma.

Demographic and Environmental Factors Associated with Mental Health: A Cross-Sectional Study.

Relevant demographic and environmental conditions need to be understood before tailoring policies to improve mental health. Using community health survey data from 25 communities in Seoul, 2013, cross-sectional associations between mental health and community level environments were assessed. Mental health outcomes (self-rated stress levels (SRS) and depressive symptoms (DS)) were analyzed. Community environmental factors included green space, green facilities, and annual PM10 level (AnnPM10); socio-demographic factors included sex, age, education, labor market participation, comorbidity, sleep hours, physical activity, smoking, and drinking. A total of 23,139 people with the following characteristics participated: men (44.2%); age groups 19-39 (36.0%), 40-59 (39.4%), 60-74 (19.2%), and 75+ (5.4%). Women had higher odds ratios (OR) for SRS [OR 1.22, 95% Confidence interval (CI) 1.17-1.27] and DS [OR 1.55, 95% CI 1.42-1.71]. Regular physical activity predicted SRS [OR 0.90, 95% CI 0.84-0.95] and DS [OR 0.98, 95% CI 0.88-1.10]; current smoking and drinking were adversely associated with both SRS and DS. Higher accessibility to green space (Q4) was inversely associated with DS [OR 0.89, 95% CI 0.81-0.97] compared to lower accessibility (Q1). AnnPM10, annual levels for particles of aerodynamic diameter <10 µm (PM10), among communities was associated with poorer SRS [OR 1.02, 95% CI 1.00-1.04] by 10 µg/m³ increases. Therefore, both demographic and environmental factors should be considered to understand mental health conditions among the general population.

Epicardial adipose tissue is related to cardiac function in elderly women, but not in men.

BACKGROUND AND AIM: Epicardial adipose tissue (EAT) is easily quantifiable visceral adipose tissue that is closely associated with cardiometabolic disease including heart failure with preserved left ventricular (LV) ejection fraction. As body fat distribution and metabolism are different between men and women, we evaluated the sex difference in EAT thickness and its relationship to cardiac function. METHODS AND RESULTS: A total of 152 consecutive patients (76 men) with mean age of 62 ± 9 years were enrolled. Conventional echocardiography was performed and EAT thickness was measured perpendicularly on the right ventricular free wall at end systole. Mean EAT thickness in all patients was 6.5 ± 2.0 mm. EAT thickness was associated with patient age, body mass index, and the presence of hypertension. EAT thickness was not different by sex in patients younger than 60 years (men, 6.4 ± 2.0 mm; women, 6.2 ± 1.8 mm, p = 0.716); however, among patients aged 60 years or older, EAT thickness was significantly greater in women than men (men, 6.0 ± 1.7 mm; women 7.7 ± 2.1 mm, p < 0.001). LV function represented by E/e' and s' was significantly related to EAT thickness only in women (E/e', ß = 0.330, p = 0.002; lateral s', ß = -0.225, p = 0.042). CONCLUSION: EAT thickness was greater in women than men after 60 years old and its relationship with LV function was significant only in women. Greater increase in EAT thickness in elderly women after menopause might partially account for this difference.

Pre-Stage Acute Kidney Injury Can Predict Mortality and Medical Costs in Hospitalized Patients.

The significance of minimal increases in serum creatinine below the levels indicative of the acute kidney injury (AKI) stage is not well established. We aimed to investigate the influence of pre-stage AKI (pre-AKI) on clinical outcomes. We enrolled a total of 21,261 patients who were admitted to the Seoul National University Bundang Hospital from January 1, 2013 to December 31, 2013. Pre-AKI was defined as a 25-50% increase in peak serum creatinine levels from baseline levels during the hospital stay. In total, 5.4% of the patients had pre-AKI during admission. The patients with pre-AKI were predominantly female (55.0%) and had a lower body weight and lower baseline levels of serum creatinine (0.63 ± 0.18 mg/dl) than the patients with AKI and the patients without AKI (P < 0.001). The patients with pre-AKI had a higher prevalence of diabetes mellitus (25.1%) and malignancy (32.6%). The adjusted hazard ratio of in-hospital mortality for pre-AKI was 2.112 [95% confidence interval (CI), 1.143 to 3.903]. In addition, patients with pre-AKI had an increased length of stay (7.7 ± 9.7 days in patients without AKI, 11.4 ± 11.4 days in patients with pre-AKI, P < 0.001) and increased medical costs (4,061 ± 4,318 USD in patients without AKI, 4,966 ± 5,099 USD in patients with pre-AKI, P < 0.001) during admission. The adjusted hazard ratio of all-cause mortality for pre-AKI during the follow-up period of 2.0 ± 0.6 years was 1.473 (95% CI, 1.228 to 1.684). Although the adjusted hazard ratio of pre-AKI for overall mortality was not significant among the patients admitted to the surgery department or who underwent surgery, pre-AKI was significantly associated with mortality among the non-surgical patients (adjusted HR 1.542 [95% CI, 1.330 to 1.787]) and the patients admitted to the medical department (adjusted HR 1.384 [95% CI, 1.153 to 1.662]). Pre-AKI is associated with increased mortality, longer hospital stay, and increased medical costs during admission. More attention should be paid to the clinical significance of pre-AKI.

Deprivation and suicide mortality across 424 neighborhoods in Seoul, South Korea: a Bayesian spatial analysis.

OBJECTIVES: A neighborhood-level analysis of mortality from suicide would be informative in developing targeted approaches to reducing suicide. This study aims to examine the association of community characteristics with suicide in the 424 neighborhoods of Seoul, South Korea. METHODS: Neighborhood-level mortality and population data (2005-2011) were obtained to calculate age-standardized suicide rates. Eight community characteristics and their associated deprivation index were employed as determinants of suicide rates. The Bayesian hierarchical model with mixed effects for neighborhoods was used to fit age-standardized suicide rates and other covariates with consideration of spatial correlations. RESULTS: Suicide rates for 424 neighborhoods were between 7.32 and 71.09 per 100,000. Ninety-nine percent of 424 neighborhoods recorded greater suicide rates than the Organization for Economic Cooperation and Development member countries' average. A stepwise relationship between area deprivation and suicide was found. Neighborhood-level indicators for lack of social support (residents living alone and the divorced or separated) and socioeconomic disadvantages (low educational attainment) were positively associated with suicide mortality after controlling for other covariates. CONCLUSIONS: Finding from this study could be used to identify priority areas and to develop community-based programs for preventing suicide in Seoul, South Korea.

Unequal geographic distribution of life expectancy in Seoul.

This study examined life expectancies in 25 gus, administrative districts of Seoul, the capital of Korea, by gender in 1995, 2002, and 2008 to explore trends in mortality inequality among areas. The authors constructed single-decrement life tables and employed between-group variance, the Theil index, and mean log deviation to measure absolute and relative disparities in life expectancy among areas during the periods 1995-2002 and 2002-2008. It was found that life expectancy gaps between gus have widened in absolute and relative terms in both genders over the decade, and that this pattern was particularly dramatic in females after 2002. This increasing gap could be attributable to the more negative health impact on females since the late 1990s stemming from the economic crisis, eventually reflected in their places of residence. Thus, a social buffer system to narrow the health gap between geographic areas and social classes must be established.