Factors Affecting the Preference for Hospitals Over Clinics in Primary Care in Korea

BACKGROUND

While the effect of gatekeeping was extensively studied, few efforts have been made to explain why the measures to strengthen gatekeeping do not work well in some countries. This study examined the patient factors related to the choice of level of health care facilities for outpatient care in Korea.

METHODS

We examined a population-based sample representative of the population of Korea aged 15 and over in the healthcare experience survey of 2021. A logistic regression model examined the factors associated with choosing hospitals or clinics for outpatient care.

RESULTS

Easy accessibility, kindness of medical staff, and recommendations from acquaintances were considered more important for those who chose clinics over hospitals. While those who chose clinics were more likely to feel that physicians and nurses more readily communicated with patients, those who chose hospitals were more likely to feel that the facility was comfortable. Whereas those who chose hospitals were more likely to trust the current health care system in Korea, those who chose clinics were more likely to think that the health care system needed to be reformed. The tendency was similar when analyzed only among those with good perceived health conditions and without chronic diseases.

CONCLUSION

This study demonstrates that the preference for hospitals over clinics is mainly based on desire rather than medical need and is not likely to be affected by measures intended to induce a voluntary change of behavior.

Depression and its associated factors: A comparison between congenital and acquired physical disabilities

OBJECTIVE

While depression associated with disability has been extensively studied, how depression could differ depending on whether the disability is congenital or acquired remains to be investigated. The objective of this study was to compare depression and its related factors among people with congenital and acquired physical disabilities.

METHODS

We used the 2016 Panel Survey of Employment for the Disabled in Korea, a population-based survey for people with disability registered with the Korean government. Among 4577 participants, a total of 2128 participants with physical disability were analyzed using Chi-square test and binary logistic regression analysis.

RESULTS

The prevalence of depression was 12.9% in those with congenital physical disability and 16.0% in those with acquired physical disability. Stress due to disability and family relationship satisfaction were associated with higher and lower odds of depression, respectively, in both disability groups. Discrimination due to disability, divorce, social participation, and subjective social status were significant predictors of depression only in people with acquired disability.

CONCLUSIONS

Compared to those with congenital disability, individuals with acquired disability can be more susceptible to issues relating to social relationship, social standing and discrimination. Findings of this study suggest that acquired disability and adapting to changes associated with it can be a source of mental distress in addition to living with it. More efforts are needed to address discrimination, provide supportive social relationships, and provide supportive living conditions in order to reduce depression in persons living with disability, especially those with acquired disability.

Factors Associated with End-Of-Life Health Care Use and Spending in Korea in Comparison with the General Population

This study investigated the factors associated with end-of-life health care use and spending in Korea. Chronically ill decedents, who were hospitalized for one of nine chronic conditions during the year before death, were identified from the National Health Insurance Database in 2017. For comparison, the end-of-life care spending for all decedents and the annual health care spending for the general population were analyzed. The inpatient and outpatient end-of-life care spending for the chronically ill decedents were sixteen and seven times the annual inpatient and outpatient spending for the general population respectively. The regional income level was positively associated with both inpatient and outpatient spending among the decedents with a stronger association in the chronically ill decedents, while a negative association was found in the general population. No significant association was found between the inpatient spending and the number of hospital beds for the chronically ill decedents, whereas the number of beds in small to medium-sized hospitals was positively associated with inpatient spending for the total decedents and the general population. The findings suggest that hospitalization for end-of-life care depends more on the income of the patients, while the inpatient spending for total decedents and the general population are more likely to be affected by the supply of beds.

The impact of the Mental Health Act revision for deinstitutionalization in Korea on the crime rate of people with schizophrenia

This study examined changes in the crime rates of people with schizophrenia in Korea in comparison with the general population after the Mental Health Act revision for deinstitutionalization in 2017. The crime rates of people with schizophrenia and the general population were calculated from 2012 to 2021 using the Korean National Policy Agency crime statistics. The effects of the law revision in 2017 on the crime rates were assessed using the interrupted time series and difference-in-difference analyses. The crime rates of people with schizophrenia tended to be lower than the general population except for murder and arson, which were 5.3 and 11.4 times, respectively, that of the general population. While no significant effect of the revision was found in the interrupted times series analysis, the difference-in-differences analysis indicated that the total crime rates and the rates of violence and public order crime increased among people with schizophrenia compared with the general population. The revision of the Mental Health Act for deinstitutionalization did not lead to an increase in the murder rate of people with schizophrenia as is commonly thought. However, the increases in overall crime and violence rates of people with schizophrenia suggest that the deinstitutionalized patients may not have been successfully relocated into the community. The increase in crime after the revision should be interpreted as a call for well-resourced community care rather than the reason for re-transfer of patients to hospitals.

The impact of the COVID-19 pandemic on suicides: A population study

This study examines the factors associated with the change in the number of suicides per month during the COVID-19 pandemic from 2019 to 2021. For economic indicators, employment and unemployment rates, Consumer Price Index, and Consumer Sentiment Index were used. As inverse indicators of social distancing, the numbers of overseas departures, domestic trips, and movie audience were used. The monthly numbers of inpatients and outpatients for depression were included to consider the effect of the prevalence of depression. Pearson's correlation coefficient analysis and a linear regression were conducted. There was a continued decrease in the number of suicides of 1.7% in 2021 from 2020 following the 4.4% decrease in the previous year. The employment rate was positively associated with the number of suicides for males, while the consumer price index was negatively associated with the number of suicides for females. While the inverse social distancing measures were positively correlated with the number of suicides, no significant association was observed in the regression analysis. Commonly shared thoughts that the pandemic would lead to an increase in suicides by its direct negative impact on mental health or indirect impact through the aggravation of economic conditions and social distancing need to be re-examined.

Comparison of the factors for suicidal ideation and suicide attempt: a comprehensive examination of stress, view of life, mental health, and alcohol use

This study was performed to examine the elements that cause suicidal ideation to develop into a suicide attempt by comparing the factors related to suicidal ideation and attempt. The subjects in the study were 5982 employees, who received mental health screening from January 2016 to December 2019 in Korea. Multivariate binary logistic regression analysis was performed with suicidal ideation and suicide attempt as dependent variables respectively. While suicidal ideation was associated with both moderate and severe grades of depression and alcohol consumption, only severe grades of depression and alcohol consumption were associated with suicide attempts. Among family, interpersonal, work-related, and financial stress, which were significant predictors of suicidal ideation, only family stress predicted suicide attempts. Whereas dissatisfaction with the present, regret for the past, and hopelessness for the future were all predictors for suicidal ideation, only regret for the past was a significant predictor of suicide attempts. The distinctive impact of family stress on suicide attempts suggests that family support can play a pivotal role in suicide prevention, and the significant impact of regret for the past on suicide attempts indicates the need for a cognitive approach in a high-risk population. Finally, the substantial impact of alcohol on suicide attempts compared to suicidal ideation suggests the importance of alcohol regulation in suicide prevention.

Suicide rates by occupation in Korea, 1993-2017: the impacts of financial crisis and suicide policy

This study compared the suicide rates among different groups of occupations in Korea and their changes from 1993 through 2017. The suicide rate tended to be low in the high skill occupations except the manager group. The suicide rates showed increases around the financial crises of 1997 and 2008 in most occupations, and the sharpest increase was observed in the managers. The suicide rate in the manager group, which was the lowest among all occupation groups until the mid 2000s, showed the sharpest increase and became the highest since 2012 among all occupation groups. The sustained reduction in suicide rates among the skilled agricultural, forestry and fishery workers in Korea, following the implementation of paraquat control since 2005, shows that means restriction is an effective and essential way for reducing suicides. While more efforts should be put into means restriction, policy makers should focus on changing public perceptions of suicide in order that it would not be accepted as a possible solution for the difficulties in life.

Alcohol consumption and suicide rate: A cross-sectional analysis in 183 countries

The age-standardized suicide rate and per capita alcohol consumption from 183 countries were acquired, and its relationship with per capita alcohol consumption was examined by the regression analysis. The positive associations between per capita alcohol consumption and the suicide rate were found among males and females in all income groups of countries. Compared with other environmental factors, controlling alcohol consumption has a distinct target and can be feasible and effective for reducing suicides. Health policy makers should keep in mind that alcohol consumption is costing lives not just by long-term physical ailments but also by making people vulnerable to suicide.

Factors associated with the suicide rates in Korea

The suicide rate in the Republic of Korea remains among the highest in the world, which needs to be examined in various aspects. This study investigated factors associated with the suicide rates in Korea. The suicide rates of 251 districts in Korea in 2015 and their relationships with the prevalence of heavy drinking, health care provision, and religion as well as demographic characteristics were examined with a Pearson correlations and a multiple linear regression analysis. The suicide rate in Korea was 26.5 per 100,000 persons in 2015. The regression analysis showed that the income level of the region, as represented by the average national health insurance premium, had a negative association with the suicide rate and that the prevalence of heavy drinking and the percentage of the population aged 65 and above had positive associations with the suicide rate. While the unemployment rate and the proportion of Catholics showed negative relationships with the suicide rate in the correlation matrix, the association was statistically insignificant in the regression analysis. Special attention should be given to excessive drinking and socio-economically disadvantaged conditions in taking measures to prevent suicide.

Crimes by people with schizophrenia in Korea: comparison with the general population

BACKGROUND

This study was performed to describe the prevalence of crimes committed by persons with schizophrenia using population-based data and to compare the crime prevalence of persons with schizophrenia and the general population.

METHODS

The number of crimes was obtained from the Korean National Policy Agency (KNPA) crime statistics (2012-2016), which provide the number of crimes in terms of the criminal's mental status and mental health conditions. For the number of persons with schizophrenia, estimates were used which had been calculated from the inpatient and outpatient claims from the National Health Insurance Service. The crime prevalence in persons with schizophrenia was calculated according to the types of crimes, and a comparison with the general population was conducted.

RESULTS

The overall crime prevalence of persons with schizophrenia was 72.7 to 90.3 per 10,000 from 2012 through 2016, which was about one fifth that of the general population. While the crime rates of the persons with schizophrenia were lower than the general population in most types of crimes including violence, intellectual crimes, and theft, the prevalence of murder, arson, and drug-related crimes in persons with schizophrenia was about five times, six times, and two times that of the general population respectively.

CONCLUSION

The higher prevalence of serious offences among persons with schizophrenia suggests the need for closer and more appropriate care for the population, which would be achieved through effective continuity of institutional and community care.

Factors associated with the rates of coronary artery bypass graft and percutaneous coronary intervention

BACKGROUND

Korea has seen a rapid increase in the use of percutaneous coronary intervention (PCI) with the ratio of PCI to coronary artery bypass graft (CABG) the highest in the world. This study was performed to examine the factors associated with the rates of CABG and PCI.

METHODS

The data were acquired from the National Health Insurance database in Korea in 2013. We calculated the age-sex standardized rates of CABG and PCI. We examined the factors associated with the CABG and PCI rates by performing a regression analysis.

RESULTS

The rate of CABG showed a negative association with the deprivation index score, and other factors, such as the number of providers or hospital beds, did not show any significant association with the CABG rate. The rate of PCI had a strong negative association with the number of cardiothoracic surgeons and a strong positive association with the number of hospital beds.

CONCLUSIONS

The positive association between the PCI rate and the number of hospital beds suggests that the use of PCI may be driven by the supply of beds, and the inverse association between the PCI rate and the number of cardiothoracic surgeons indicates the overuse of PCI due to lack of the providers of CABG. Policy measures should be taken to optimize the use of revascularization procedures, the choice of which should primarily be based on the patient's need.

Geographic variation and factors associated with rates of knee arthroplasty in Korea-a population based ecological study

Background

The recent increase in knee arthroplasty (KA) use in Korea is among the highest in the world. The rapid increase in KA use suggests that the KA use in Korea could have been affected by medically unjustifiable factors. This study aimed to examine the geographic variation in the rate of KA and its associated factors in Korea.

Methods

We used the data from the National Health Insurance in Korea in 2013, from which a total of 67,086 claims for KA were obtained. We calculated the age-sex-standardized KA rates of the entire population and the crude rates of the age groups 0–64 and 65 and over in 251 districts. We assessed the geographic variation of the KA rates and examined the associated factors with a multivariate linear regression with the KA rate as a dependent variable.

Results

The overall rate of KA in Korea was 132.7 per 100,000 persons. The rates of KA showed a four-fold variation. The deprivation index score and the number of beds in the small to medium sized hospitals showed a positive association with the rates of KA while the number of orthopedic surgeons showed a negative association.

Conclusions

Korea has been experiencing a rapid increase in the use of KA for the last decade or so, which was most prominent among the elderly population aged 65 and older. Our results suggest that the higher rate of KA is strongly related to a higher supply of beds and the socioeconomically deprived conditions. Considering that the decision concerning KA has room for discretion and also affects a considerable portion of health care expenditures, the use of KA should be thoroughly monitored with more emphasis on standardization in the decision making process and preventive measures that can lessen the need for KA.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2766-y) contains supplementary material, which is available to authorized users.

An ecological study of geographic variation and factors associated with cesarean section rates in South Korea

BACKGROUND

Korea is in a condition where the impact of patient and supplier factors on cesarean section rates can be clearly described. The cesarean section rates in Korea are among the highest in the world while the number of obstetricians is decreasing sharply. This study aimed to investigate the geographic variation in cesarean section rates in Korea and its factors.

METHODS

The data were obtained from the National Health Insurance database in Korea in 2013. We calculated the age-standardized and crude cesarean section rates of 251 districts in Korea and variation statistics. A linear regression analysis was performed to determine factors for cesarean section rates.

RESULTS

The overall cesarean section rate in Korea was 364.6 cases per 1000 live births. The deprivation index score was strongly associated with the increase in the cesarean section rate while the density of hospital obstetricians and hospital beds showed a negative association. Average maternal age and total fertility rate showed a negative relationship with the cesarean section rate.

CONCLUSIONS

Korea is suffering from a continuing decrease in obstetricians. Our study shows that this decline has more of an effect on mothers in the disadvantaged areas. Securing equal access to obstetric care among areas is necessary, and measures to encourage obstetricians and mothers not to opt for cesarean section are required.

Hospitalizations for ambulatory care sensitive conditions as an indicator of access to primary care and excess of bed supply

BACKGROUND

Ambulatory care sensitive conditions (ACSC) hospitalization is a widely accepted measure of the access to primary care. However, given its discretionary characteristics, the ACSC hospitalization can be a measure reflecting the influence of hospital bed supply. In Korea, where the quality of primary care and oversupply of hospital beds are coexistent concerns, ACSC hospitalization can be used to examine the impact of both factors. This study was performed to investigate the ACSC hospitalization rate as a measure of the hospital bed supply as well as access to primary care.

METHODS

Data were obtained from the National Health Insurance Database for 2015. We calculated the age-sex standardized hospitalization rates for ACSC in the total population and crude rates of ACSC hospitalization for three different age groups in 252 districts in Korea. We calculated the variation statistics of ACSC hospitalization rates, and we estimated a linear regression model to investigate the factors for ACSC hospitalization.

RESULTS

There was a very high geographic variation in ACSC hospitalization rates. Higher density of primary care physicians was associated with a decreased ACSC hospitalization rate while a higher density of hospital beds in small to medium sized hospitals was associated with an increased rate. The deprivation index score had a strongly positive association with the ACSC hospitalization rates.

CONCLUSION

ACSC hospitalization, while being a negative index of primary care access, can also be a measure indicating the impact of the hospital bed supply, and it is still a valid measure of the disparity of health care, the original motivation for this topic.

A spatial analysis of geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea

Background

The incidence of pneumonia in Korea started to increase in the 1990’s after a period of decrease and stabilization, and the mortality and hospitalization rates for pneumonia in Korea are alarmingly high. This study was performed to examine geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea.

Methods

Data were acquired from the inpatient claims of the 2015 period of the National Health Insurance Service. The age- and sex-standardized hospitalization rates for bacterial pneumonia were calculated for three age groups. Geographic variation was measured with the coefficient of variation, the ratio of the 90th to the 10th percentile of the distribution of rates, and the systematic component of variation. Considering the results of Moran’s I statistic which suggested spatial autocorrelation, we estimated spatial regression models using spatial error models.

Results

The hospitalization rate for bacterial pneumonia was 79.1 per 10,000 population, and the rate was the highest in the age group 0–14 at 325.3, and it was 161.5 among the elderly. The geographic variation statistics showed high variation with the coefficient variation at 0.6. The deprivation score showed positive associations, and the number of primary care physicians had a negative association with the hospitalization rates across all age groups but the age group 0–14. The number of beds in hospitals with less than 300 beds had a positive association with the hospitalization rates for bacterial pneumonia, and the impact was the strongest in the age group 0–14.

Conclusions

The present study shows that pneumonia can be a major public health issue even in a developed country. Socioeconomic conditions can still be a concern for pneumonia in developed countries, and the role of primary care physicians in preventing hospitalization for bacterial pneumonia needs to be recognized. Most of all, the strong impact of hospital beds on the hospitalization rates for pneumonia, especially for the children, should be addressed. High disease burden of pneumonia in Korea can partly be attributable to oversupply of hospital beds. These factors should be taken into consideration in establishing policy measures for the rise in pneumonia.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0798-6) contains supplementary material, which is available to authorized users.

Rethinking the Role of the Public Health Clinic: Comparison of Outpatient Utilization in the Public Health Clinics and Private Clinics in Korea

Korea has experienced an overall expansion of access to care in the past few decades, which necessitated the reconsideration of the role of the public health clinics (PHC) as a primary care provider. The recent controversy about the outpatient copayment waiver for the elderly in the PHC is in the same vein. This study compared the outpatient utilization of the PHC and private clinics, and investigated its factors. Data were acquired from the National Patient Sample in 2013. Compared with private clinics, the patients in the PHC were more elderly and had less severe conditions. Being elderly, the status of National Health Insurance (NHI) beneficiaries, less comorbidities, and low total claim costs were found to be factors for choosing the PHC over private clinics. These results suggest that the elderly, who are the main beneficiaries of copayment waivers in the PHC, are the most likely to use the outpatient service by the PHC. The functions of the PHC need to be rearranged according to the recent advancements in the health care system in Korea. Diverting the resources and efforts from outpatient care to functions that best serve the health of the population should be considered.

Primary Care Patients' Preference for Hospitals over Clinics in Korea

Korea is in a unique condition to observe whether patients, when equal access to the levels of health care facilities is guaranteed by the support of the national health insurance, choose the appropriate levels of health care facilities. This study was performed to investigate the primary care patients’ preference for hospitals over clinics under no restriction for their choice. We used the 2011 National Inpatient Sample database of the Health Insurance Review and Assessment Service in Korea. A primary care patient was defined as a patient who visited as an outpatient in health care facilities with one of the 52 minor conditions defined by the Korean government. We found that approximately 15% of outpatient visits of the patients who were eligible for primary care in Korea happened in hospitals. In terms of cost, the outpatient visits in hospitals accounted for about 29% of total cost of outpatient visits. This arbitrary access to hospitals can lead to an inefficient use of health care resources. In order to ensure that health care facilities are stratified in terms of access as well as size and function, interventions to distribute patients to the appropriate level of care are required.

Emergency department utilization among people with disabilities in Korea

BACKGROUND

According to prior studies, it is possible to consider the emergency care utilization due to ambulatory care sensitive conditions (ACSCs) as a proxy measure of access to primary care but there was no confirmed study among people with disabilities.

OBJECTIVE/HYPOTHESIS

We examined overall emergency department (ED) utilization patterns among people with disabilities compared with the general population and estimated factors affecting ED utilization. Additionally, we examined whether there were any differences in ED visits due to ACSCs according to type and severity of disability.

METHODS

The nationally representative Korean Health Panel Survey was used. Data from 14,616 individuals who participated in the survey from 2008 to 2012 were analyzed. The frequency and causes of emergency visits were examined between individuals with and without disabilities. A generalized regression model with Poisson distribution was applied to identify factors that affect ED visits.

RESULTS

In 2012, people with disabilities were about two times as likely to visit the ED compared to people without disabilities, and people with external disability represented the largest proportion of people with disabilities. According to generalized linear model, disability was a strong predictor of ED visits, along with lower education level, being elderly, having a chronic disease, and being less healthy. Overall, ED visits due to ACSCs were about three times higher in the disabled group than in the non-disabled group.

CONCLUSIONS

Public health authorities should consider strengthening the primary care system to avoid unnecessary and preventable ED utilization among all Korean people, including people with disabilities.

The Effect of Geographic Units of Analysis on Measuring Geographic Variation in Medical Services Utilization

Objectives:

We aimed to evaluate the effect of geographic units of analysis on measuring geographic variation in medical services utilization. For this purpose, we compared geographic variations in the rates of eight major procedures in administrative units (districts) and new areal units organized based on the actual health care use of the population in Korea.

Methods:

To compare geographic variation in geographic units of analysis, we calculated the age–sex standardized rates of eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee-replacement surgery, caesarean section, hysterectomy, computed tomography scan, and magnetic resonance imaging scan) from the National Health Insurance database in Korea for the 2013 period. Using the coefficient of variation, the extremal quotient, and the systematic component of variation, we measured geographic variation for these eight procedures in districts and new areal units.

Results:

Compared with districts, new areal units showed a reduction in geographic variation. Extremal quotients and inter-decile ratios for the eight procedures were lower in new areal units. While the coefficient of variation was lower for most procedures in new areal units, the pattern of change of the systematic component of variation between districts and new areal units differed among procedures.

Conclusions:

Geographic variation in medical service utilization could vary according to the geographic unit of analysis. To determine how geographic characteristics such as population size and number of geographic units affect geographic variation, further studies are needed.

Evaluation of Geographic Indices Describing Health Care Utilization

Objectives

The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization.

Methods

We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates.

Results

In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index.

Conclusions

Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.

Associations of multicultural status with depressive mood and suicidality among Korean adolescents: the roles of parental country of birth and socioeconomic position

Background

The mental health of the offspring of immigrants is a major public health concern. In this study, we examined associations of multicultural status and parental country of birth with adolescent mental health in South Korea, and assessed the effect of socioeconomic position (SEP) on these associations.

Methods

We used four waves of the Korea Youth Risk Behavior Web-based Survey (KYRBS) between 2011 and 2014, including 294,324 participants (149,219 boys and 145,105 girls aged 13–18 years) as study subjects. KYRBS is a cross-sectional survey conducted annually by the Korea Centers for Disease Control and Prevention. The participants in the KYRBS were drawn as stratified multistage clustered samples from Korean middle schools and high schools. We calculated the age-adjusted 12-month prevalence of depressive mood and suicidal behaviors by parental country of birth, and estimated the effects of SEP indicators on the relationship.

Results

The age-standardized prevalence of suicidality (suicide ideation, plans, and attempts) was significantly different between multicultural and non-multicultural boys. The impact of multicultural status on mental health varied with parental foreign-born status and maternal country of birth. Compared with non-multicultural counterparts, boys with Japan-born mothers showed lower prevalence ratios (PRs) of suicidal plans (PR = 0.34, 95% CI 0.16–0.70). Girls with Japan-born mothers also showed lower PRs of depressive mood (PR = 0.77, 95% CI 0.63–0.95) and suicidal ideation (PR = 0.59, 95% CI 0.41–0.83), while adolescents with Korean-Chinese mothers showed similar PRs. Boys with foreign-born fathers as well as boys with two foreign-born parents were at a greater risk of suicidality than non-multicultural boys. The magnitude of the relationship between multicultural status and mental health outcomes was generally attenuated after adjusting for SEP indicators.

Conclusions

In general, adolescents with Japan-born mothers showed lower PRs of depressive mood and suicidality than non-multicultural adolescents, while those with Korean-Chinese mothers showed similar PRs. Boys who had foreign-born fathers generally showed greater PRs of depressive mood and suicidality than non-multicultural boys. To ensure the effective implementation of policies to reduce mental health problems among multicultural adolescents in South Korea, detailed information should be considered regarding the cultural and socioeconomic backgrounds of families, such as parental country of birth and SEP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4044-y) contains supplementary material, which is available to authorized users.

Why do psychiatric patients in Korea stay longer in hospital?

Korea is the only developed country that saw an increase in the number of psychiatric beds with the longest average length of stay of psychiatric patients for the past decades. This phenomenon can be explained regarding the payment system, the law, and society. Korea is in a critical position concerning mental health policy. How it paves the way for reducing psychiatric admissions will provide a model for rearranging the interests of different social groups for the sake of a higher value, that of human rights.

Maternally-derived zinc transporters ZIP6 and ZIP10 drive the mammalian oocyte-to-egg transition

Rapid cellular zinc influx regulates early mammalian development during the oocyte-to-egg transition through modulation of the meiotic cell cycle. Despite the physiological necessity of this zinc influx, the molecular mechanisms that govern such accumulation are unknown. Here we show that the fully grown mammalian oocyte does not employ a transcriptionally based mechanism of zinc regulation involving metal response element-binding transcription factor-1 (MTF-1), as demonstrated by a lack of MTF-1 responsiveness to environmental zinc manipulation. Instead, the mammalian oocyte controls zinc uptake through two maternally derived and cortically distributed zinc transporters, ZIP6 and ZIP10. Targeted disruption of these transporters using several approaches during meiotic maturation perturbs the intracellular zinc quota and results in a cell cycle arrest at a telophase I-like state. This arrest phenocopies established models of zinc insufficiency during the oocyte-to-egg transition, indicating the essential function of these maternally expressed transporters. Labile zinc localizes to punctate cytoplasmic structures in the human oocyte, and ZIP6 and ZIP10 are enriched in the cortex. Altogether, we demonstrate a mechanism of metal regulation required for female gamete development that may be evolutionarily conserved.

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems.

Object level HSI-LIDAR data fusion for automated detection of difficult targets

Data fusion from disparate sensors significantly improves automated man-made target detection performance compared to that of just an individual sensor. In particular, it can solve hyperspectral imagery (HSI) detection problems pertaining to low-radiance man-made objects and objects in shadows. We present an algorithm that fuses HSI and LIDAR data for automated detection of man-made objects. LIDAR is used to define a set of potential targets based on physical dimensions, and HSI is then used to discriminate between man-made and natural objects. The discrimination technique is a novel HSI detection concept that uses an HSI detection score localization metric capable of distinguishing between wide-area score distributions inherent to natural objects and highly localized score distributions indicative of man-made targets. A typical man-made localization score was found to be around 0.5 compared to natural background typical localization scores being less than 0.1.

Alterations of A549 lung cell gene expression in response to biochemical toxins

Health risks associated with the inhalation of potentially toxic materials have been a topic of great public concern. In vitro cellular analyses can provide mechanistic information on the molecular-level responses of lung-derived cell lines to a variety of these hazards. This understanding may be used to develop methods to reduce the damage from such toxins or to detect early stages of their effects. Here we describe an evaluation of the alterations in gene expression of an immortalized lung cell line (A549, human type II epithelia) to a variety of inhalation health hazards including etoposide, gliotoxin, streptolysin O, methyl methansesulfonate (MMS), and Triton X-100. The A549 cells display a dose-response relationship to each toxin with initial responses including alterations in metabolic activity, increases in membrane permeability, and initiation of response genes. In general, membrane-damaging agents (streptolysin O and Triton X-100) induce production of new ion channel proteins, structural proteins, and metabolic enzymes. Gliotoxin impacted the metabolic machinery, but also altered ion channels. Etoposide and MMS caused alterations in the cell cycle, induced DNA repair enzymes, and initiated apoptotic pathways, but MMS also induced immune response cascades. The mechanism of cell response to each toxin is supported by physiological analyses that indicated a fairly slow initiation of cell response to all compounds tested, except for Triton, which caused rapid decline in cell function due to solubilization of the cell membrane. However, Triton does induce production of a number of cell membrane-associated proteins and so its effects at low concentrations are likely translated throughout the cell. Together these results indicate a broader array of cellular responses to each of the test toxins than have previously been reported.

Ultrafast laser-induced phase transitions in amorphous GeSb films

Time-resolved measurements of the spectral dielectric function reveal new information about ultrafast phase transitions induced by femtosecond laser pulses in Sb-rich amorphous GeSb films. The excitation generates a nonthermal phase within 200 fs. The dielectric function of this phase differs from that of the crystalline phase, contrary to previous suggestions of a disorder-to-order transition. The observed dielectric function is close to that of the liquid phase, indicating an ultrafast transition from the amorphous phase to a different disordered state.

Inverted double-gap isolation chamber for high-resolution calcium fluorimetry in skeletal muscle fibers

Here we describe an improved inverted double-grease-gap isolation chamber that allows the formation of grease seals of high mechanical stability and high electrical resistance. We also provide a detailed description of the procedure used to mount the muscle fibers onto the apparatus. The new chamber permits the electrophysiological study of muscle fibers using an inverted microscope and high-resolution objectives, thus complying with the requirements of modern fluorescence confocal detection methods. The simplicity and reliability of the mounting procedure make this chamber preferable over other gap isolation chambers currently used for simultaneous electrophysiological and optical studies of calcium release. Experimental results obtained from amphibian muscle fibers are presented to illustrate the performance of the chamber when using global fluorescence detection, confocal spot detection, and laser confocal scanning imaging.

Supercharging accelerates T-tubule membrane potential changes in voltage clamped frog skeletal muscle fibers

In voltage-clamp studies of single frog skeletal muscle fibers stained with the potentiometric indicator 1-(3-sulfonatopropyl)-4-[beta[2-(di-n-octylamino)-6-naphthyl] vinyl]pyridinium betaine (di-8 ANEPPS), fluorescence transients were recorded in response to both supercharging and step command pulses. Several illumination paradigms were utilized to study global and localized regions of the transverse tubule system (T-system). The rising phases of transients obtained from global illumination regions showed distinct accelerations when supercharging pulses were applied (95% of steady-state fluorescence achieved in 1.5 ms with supercharging pulses versus 14.6 ms with step pulses). When local transients were recorded at the edge of the muscle fiber, their kinetics resembled those of the applied waveform, but a similar relationship was not observed in transients from regions near the edge chosen to minimize the surface membrane contribution. We developed a model of the T-system capable of simulating membrane potential changes as a function of time and distance along the T-system cable and the associated fluorescence changes in regions corresponding to the experimental illumination strategies. A critical parameter was the access resistance term, for which values of 110-150 Omega.cm2 were adequate to fit the data. The results suggest that the primary mechanism through which supercharging pulses boost the kinetics of T-system voltage changes most likely involves their compensating the voltage attenuation across the access resistance at the mouth of the T-tubule.

Fast voltage gating of Ca2+ release in frog skeletal muscle revealed by supercharging pulses

1. In single frog skeletal muscle fibres, we utilized supercharging voltage clamp command pulses to boost the rate of depolarization in the transverse tubular system (T-system) such that 95 % of steady-state potential is achieved in < 2 ms (as indicated by fluorescent potentiometric dye signals detected from a global illumination region). Signals detected near the edge of muscle fibres indicate that peripheral regions of the T-system are not significantly overcompensated under these conditions. 2. We explored the impact of accelerating T-system depolarization on voltage-dependent events of excitation-contraction (E-C) coupling by measuring charge movement currents (CMCs) and Ca2+ fluorescence transients in response to both supercharging and conventional step pulses. 3. When compared with CMCs elicited by step pulses, supercharging CMCs are larger, and their kinetics more closely resemble those of gating current records reported for ionic channels. Furthermore, they decay bi-exponentially (tau fast range, 1.3-1.8 ms; tau slow range, 7.3-11.9 ms), whereas step CMCs fall with a single exponential time course (tau range, 12.5-26.7 ms). 4. Similarly, supercharging produces a distinct acceleration in Ca2+ release transients, which show little evidence of the voltage-dependent onset latencies previously encountered using step pulses. 5. The use of this novel methodology in skeletal muscle unveils a previously undetected component of charge movement, the rapid, voltage-dependent recruitment of which may provide the basis for understanding the fast gating of physiological E-C coupling.

Kinetic properties of DM-nitrophen and calcium indicators: rapid transient response to flash photolysis

We describe a high temporal resolution confocal spot microfluorimetry setup which makes possible the detection of fluorescence transients elicited by Ca2+ indicators in response to large (50-200 microM), short duration (< 100 ns), free [Ca2+] transients generated by laser flash photolysis of DM-nitrophen (DM-n; caged Ca2+). The equilibrium and kinetic properties of the commercially available indicators Fluo-3, Rhod-2, CalciumOrange-5N (COr-5N) and CalciumGreen-2 (CGr-2) were determined experimentally. The data reveal that COr-5N displays simple, fast response kinetics while, in contrast, Fluo-3, Rhod-2 and CGr-2 are characterized by significantly slower kinetic properties. These latter indicators may be unsuitable for tracking Ca2+ signaling events lasting only a few milliseconds. A model which accurately predicts the time course of fluorescence transients in response to rapid free [Ca2+] changes was developed. Experimental data and model predictions concur only when the association rate constant of DM-n is approximately 20 times faster than previously reported. This work establishes a quantitative theoretical framework for the study of fast Ca2+ signaling events and the use of flash photolysis in cells and model systems.

A gap isolation method to investigate electrical and mechanical properties of fully contracting skeletal muscle fibers

We describe here a single-gap isolation method that allows the simultaneous measurement of electrical activity and tension output from fully contracting segments of frog skeletal muscle fibers. By using single pulses and pulse trains of varying frequency (5-100 Hz), records obtained for both electrical and mechanical fiber response demonstrate that the physiological properties of the fiber segments have been preserved. Action potentials could be recorded free of movement artifacts, even while segments were in fused tetani and developing maximum tensions of more than 600 kN/m2. Single current pulses evoked action potentials that averaged 144 +/- 16 mV (mean +/- SD, n = 8) in amplitude and twitches that averaged 285 +/- 66 kN/m2 and 55 +/- 5 ms (mean +/- SD, n = 20) in magnitude and time to peak, respectively. Trains of action potentials elicited patterns of tension development that exhibited summation, unfused tetani, and fused tetani in a frequency-dependent manner. The AC and DC electrical properties of the single grease gap were modeled with a simple Thévenin equivalent circuit, which satisfactorily predicted the experimental results. Our methodology is easily implemented and potentially applicable to any muscle preparation in which fiber segments with an intact end attached to a piece of tendon can be dissected.

[Management of elderly patients with aneurysmal subarachnoid hemorrhage]

Clinical features of 61 elderly patients aged over 70 years with ruptured intracranial aneurysms were compared with those of 328 younger patients aged under 70 years. According to a policy of early operation, elderly patients with Hunt and Kosnik's grade I, II and younger patients with grade I, II, III were operated on in the acute stage. In elderly patients with grade III, IV and younger patients with grade IV, the indication for surgery was determined case by case. Surgery was performed on 29 patients (48%) in the elderly group and 277 patients (86%) in the younger group. Our conclusions are as follows: 1. Regarding cases of grade I, II and III of Hunt and Kosnik's classification, the rate of good outcome in the elderly group was similar to that in the younger group, following early surgery and meticulous post-operative care. 2. In the elderly group, no patient in cases of grade IV obtained good surgical outcome. 3. Symptomatic vasospasm was less frequent in elderly patients (18.8%) than in younger cases (37%). 4. Delayed operation was planned for some patients in the elderly group, but none of them underwent surgery because of rerupture of aneurysms and deterioration of general condition.

Study of preneoplastic changes of liver cells by immunohistochemical and molecular hybridization techniques

The status of hepatitis B virus DNA was investigated by in situ hybridization in multifocal areas of a noncancerous hepatitis B virus-associated cirrhosis. This liver exhibited a marked degree of dysplasia and adenomatous hyperplasia. The results of these studies were correlated with the histopathology and immunohistochemical stains for hepatitis B core and surface antigens. There was clear evidence of a marked reduction to absence of hepatitis B viral DNA by in situ hybridization and absence of HBc and HBsAg in the foci of liver cell dysplasia and adenomatous hyperplasia. These results support the hypothesis that liver cell dysplasia and adenomatous hyperplasia are preneoplastic in nature.