Hydraulic containment of TCE contaminated groundwater using pulsed pump-and-treat: Performance evaluation and vapor intrusion risk assessment.

Remedial actions for groundwater contamination such as containment, in-situ remediation, and pump-and-treat have been developed. This study investigates the hydraulic containment of Trichloroethylene (TCE) contaminated groundwater by using pulsed pump-and-treat technology. The hypothetical research site assumed the operation of pulsed pump-and-treat to manage groundwater contaminated with 0.1 mg/L of TCE. at the pump-and-treat facility. Numerical models, employing MODFLOW and MT3DMS for groundwater flow and contamination simulations, were used for case studies to evaluate the performance and risks of pump-and-treat operation strategies. Evaluation criteria included capture width, removal efficiency, and contaminant leakage. Health risks from TCE leakage were assessed using a vapor intrusion risk assessment tool in adjacent areas. In the facility-scale case study, the capture width of the pump-and-treat was controlled by pumping/injection well operations, including schedules and rates. Pumping/injection well configurations impacted facility efficiencies. Pulsed operation led to TCE leakage downstream. Site-scale case studies simulated contaminant transport through pump-and-treat considering various operation stages (continuous; pulsed), as well as various reactions of TCE in subsurface environment (non-reactive; sorption; sorption and biodegradation). Assuming non-reactive tracer, TCE in groundwater was effectively blocked during continuous operation stage but released downstream in the following pulsed operation stage. Considering chemical reactions, the influences of the pump-and-treat operation followed similar trends of the non-reactive tracer but occurred at delayed times. Groundwater contamination levels were reduced through biodegradation. Cancer and non-cancer risks could occur at points of exposure (POEs) where the contamination levels approached or fell below TCE groundwater standards.

Water quality seasonal variation assessment of the Gongji and Yaksa streams, Chuncheon, South Korea.

Gongji Stream flows into Lake Uiam, a potable water source for the capital region of Chuncheon, South Korea. Algal blooms often occur downstream of the Gongji stream in combination with drastic flow rate variations. Downstream water quality may also be affected by Yaksa stream. Yaksa stream joins Gongji stream before it reaches Uiam Lake, which is a drinking water source for the city. Limited data exists on the Yaksa stream water quality. Therefore, water quality parameters (pH, electrical conductivity (EC), biological oxygen demand (BOD), total nitrogen (T-N), total phosphorous (T-P), chlorophyll-a (Chl-a), total coliforms, and Escherichia coli (E. coli) concentration) were sampled from Gongji (at sites GJ1 and GJ2) and Yaksa (at sites YS1 and YS2) streams from May to September, 2022. The results revealed the overall water quality of both streams was good (BOD = 0.27-3.66 mg/L; TP = 0.003-0.074 mg/L), except on August 3. On August 3, the concentrations of BOD, TP, total coliforms, and E. coli were elevated, with the highest concentrations in samples from GJ2. The recent heavy rainfall potentially caused sewage inflows near GJ2. The correlation analysis revealed positive linear relationships in the 1-day cumulative precipitation with BOD (r = 0.503), total coliforms (r = 0.547), and TP (r = 0.814). The Yaksa stream may be an Anabaena sp. source, which contaminated samples from YS1, YS2, and GJ2, but not at GJ1 (upstream of the tributary).

Association between private health insurance and medical use by linking subjective health and chronic diseases.

This empirical study identifies the negative aspects of private health insurance (PHI) by analyzing the association between subjective health conditions, 2 weeks of outpatient care, chronic diseases, and hospitalizations for 1 year. We used frequency analysis, χ2 testing, an analysis of variance, and logistic and multiple logistic regression models to analyze the association between PHI and subjective health conditions, outpatient care, chronic disease status, and hospitalization. The PHI group had good subjective health but had more outpatient care for 2 weeks. There were few chronic diseases in the private insurance group, and there was no significant difference in hospitalizations for 1 year. Hospitalization may occur when essential medical care is required, regardless of health insurance type. This study confirmed that as the PHI lowers the burden of personal medical expenses, the PHI can lead to an increase in the medical resource expenditures on the outpatient medical service and higher public health costs. The government should work to redefine the role of private and national health insurance. Also, the effectiveness of PHI should be reevaluated so that it does not lead to indiscriminate use of medical services by minimizing the burden of private insurance.

Deep learning-based image reconstruction of 40-keV virtual monoenergetic images of dual-energy CT for the assessment of hypoenhancing hepatic metastasis.

OBJECTIVES: To evaluate the diagnostic value of deep learning model (DLM) reconstructed dual-energy CT (DECT) low-keV virtual monoenergetic imaging (VMI) for assessing hypoenhancing hepatic metastases. METHODS: This retrospective study included 131 patients who underwent contrast-enhanced DECT (80-kVp and 150-kVp with a tin filter) in the portal venous phase for hepatic metastasis surveillance. Linearly blended images simulating 100-kVp images (100-kVp), standard 40-keV VMI images (40-keV VMI), and post-processed 40-keV VMI using a vendor-agnostic DLM (i.e., DLM 40-keV VMI) were reconstructed. Lesion conspicuity and diagnostic acceptability were assessed by three independent reviewers and compared using the Wilcoxon signed-rank test. The contrast-to-noise ratios (CNRs) were also measured placing ROIs in metastatic lesions and liver parenchyma. The detection performance of hepatic metastases was assessed by using a jackknife alternative free-response ROC method. The consensus by two independent radiologists was used as the reference standard. RESULTS: DLM 40-keV VMI, compared to 40-keV VMI and 100-kVp, showed a higher lesion-to-liver CNR (8.25 ± 3.23 vs. 6.05 ± 2.38 vs. 5.99 ± 2.00), better lesion conspicuity (4.3 (4.0-4.7) vs. 3.7 (3.7-4.0) vs. 3.7 (3.3-4.0)), and better diagnostic acceptability (4.3 (4.0-4.3) vs. 3.0 (2.7-3.3) vs. 4.0 (4.0-4.3)) (p < 0.001 for all). For lesion detection (246 hepatic metastases in 68 patients), the figure of merit was significantly higher with DLM 40-keV VMI than with 40-keV VMI (0.852 vs. 0.822, p = 0.012), whereas no significant difference existed between DLM 40-keV VMI and 100-kVp (0.852 vs. 0.842, p = 0.31). CONCLUSIONS: DLM 40-keV VMI provided better image quality and comparable diagnostic performance for detecting hypoenhancing hepatic metastases compared to linearly blended images. KEY POINTS: • DLM 40-keV VMI provides a superior image quality compared with 40-keV or 100-kVp for assessing hypoenhancing hepatic metastasis. • DLM 40-keV VMI has the highest CNR and lesion conspicuity score for hypoenhancing hepatic metastasis due to noise reduction and structural preservation. • DLM 40-keV VMI provides higher lesion detectability than standard 40-keV VMI (p = 0.012).

A Framework for Systematic Assessment of Clinical Trial Population Representativeness Using Electronic Health Records Data.

BACKGROUND: Clinical trials are the gold standard for generating robust medical evidence, but clinical trial results often raise generalizability concerns, which can be attributed to the lack of population representativeness. The electronic health records (EHRs) data are useful for estimating the population representativeness of clinical trial study population. OBJECTIVES: This research aims to estimate the population representativeness of clinical trials systematically using EHR data during the early design stage. METHODS: We present an end-to-end analytical framework for transforming free-text clinical trial eligibility criteria into executable database queries conformant with the Observational Medical Outcomes Partnership Common Data Model and for systematically quantifying the population representativeness for each clinical trial. RESULTS: We calculated the population representativeness of 782 novel coronavirus disease 2019 (COVID-19) trials and 3,827 type 2 diabetes mellitus (T2DM) trials in the United States respectively using this framework. With the use of overly restrictive eligibility criteria, 85.7% of the COVID-19 trials and 30.1% of T2DM trials had poor population representativeness. CONCLUSION: This research demonstrates the potential of using the EHR data to assess the clinical trials population representativeness, providing data-driven metrics to inform the selection and optimization of eligibility criteria.

Effect of individuals' forecast for their children's economic environment and satisfaction with their relationships with children on their mortality.

AIM: The aim of this study is to evaluate if the risk of mortality among the elderly Korean individuals is associated with any of the two intergenerational variables: participants' forecast for their children's economic environment (FCEE) and participants' satisfaction with their relationship with their children (SRC). METHODS: Data from the Korean Longitudinal Study of Aging (KLoSA) conducted between 2006 and 2016 were examined. In total, 9937 individuals were included at baseline. The FCEE and SRC were measured using an 11-point Likert scale, which were stratified into four levels: "negative" (0-2), "Moderately negative" (3-5), "moderately positive" (6-8) and "positive" (9, 10). RESULTS: The Cox proportional hazards model was used to calculate hazard ratios of all-cause mortality across different levels of FCEE and SRC while adjusting for other bio-psycho-social variables. Post-hoc subgroup analyses were conducted to examine how potential confounders contribute to the associations found in our study. Multivariate analyses showed that individuals with more negative FCEE were associated with a greater risk of all-cause mortality. Compared with the "positive" FCEE group, the "negative" group showed a 30.6% increase risk of all-cause mortality (hazard ratio = 1.306, 95% confidence interval = 1.066-1.601, P = 0.010). CONCLUSION: The SRC did not exhibit any significant association with the all-cause mortality per multivariate analyses. More negative FCEE was associated with greater all-cause mortality. The FCEE, an individual's appraisal of the financial climate of their children's generation, may be considered a novel correlate of the all-cause mortality in an elderly population. Geriatr Gerontol Int ••; ••: ••-•• Geriatr Gerontol Int 2021; 21: 568-576.

Associations between Dental Checkups and Unmet Dental Care Needs: An Examination of Cross-Sectional Data from the Seventh Korea National Health and Nutrition Examination Survey (2016-2018).

To identify gender- and age-related associations between adult dental checkups and unmet dental care needs, we analyzed data of 14,000 participants, from the Seventh Korea National Health and Nutrition Examination Survey (2016-2018). Data were collected via self-report questionnaires and interviews. The complex sample chi-square test and multiple logistic regression analysis indicated that 31.7% of participants had unmet dental care needs. Within the previous 12 months, 56.5% did not undertake dental checkups, and 29.3% did not use a dental service. Odds ratios (ORs) of the unmet dental needs were 8.87 (confidence interval (CI) = 7.80-10.09, p < 0.001) for those who did not use dental services and 1.28 (CI = 1.13-1.44, p < 0.001) for those who did not have dental checkups. Significant age-dependent associations between those not receiving dental checkups and the rate of unmet dental care included men and women aged 50-59 years and women ≥70 years. However, unmet dental care needs for men aged ≥70 years not undergoing dental checkups were not statistically significant (p = 0.311). Overall, it was found that the use of dental service and dental checkups were the influencing factors for unmet dental care needs.

Difficulty in distinguishing malignant gastric lymphoma from advanced gastric cancer: Focusing on endoscopic findings of the Borrmann type.

ABSTRACT: Malignant gastric lymphoma (MGL) accounts for a small proportion (upto 5%) of gastric malignancies. However, unlike for advanced gastric cancer (AGC) that requires surgical treatment, the standard treatments for MGL are chemotherapy and radiotherapy. Hence, the initial impression of the endoscopist is critical for the differential diagnosis and for planning future treatment. The purpose of this study was to assess the endoscopic diagnostic accuracy and the possibility of distinguishing between AGC and MGL depending on the endoscopist's experience.A total of 48 patients who had MGL, and 48 age and sex-matched patients who had AGC were assessed by endoscopic review at a tertiary referral hospital between June 2008 and February 2017. Two endoscopic specialists reviewed the endoscopic findings and divided these diagnoses into 5 groups: Borrmann type (1, 2, 3, and 4) and early gastric cancer-like type. After this, 7 experts and 8 trainees were asked to complete a quiz that was comprised of 6 images for each of the 96 cases and to provide an endoscopic diagnosis for each case. The test results were analyzed to assess the diagnostic accuracy according to the pathologic results, endoscopic subgroups, and endoscopists' experience. For inter-observer agreement was calculated with Fleiss kappa values.The overall diagnostic accuracy of endoscopic findings by the experts was 0.604 and that by the trainees was 0.493 (P = .050). There was no significant difference in the diagnosis according to the final pathology (lymphoma cases, 0.518 vs 0.440, P = .378; AGC cases, 0.690 vs 0.547, P = .089, respectively). In the subgroup analysis, the experts showed significantly higher diagnostic accuracy for the endoscopic Borrmann type 4 subgroup, including lymphoma or AGC cases, than the trainees (P = .001). Inter-observer agreement of final diagnosis (Fleiss kappa, 0.174) and endoscopic classification groups (Fleiss kappa, 0.123-0.271) was slightly and fair agreement.The experts tended to have a higher endoscopic diagnostic accuracy. Distinguishing MGL from AGC based on endoscopic findings is difficult, especially for the beginners. Even if the endoscopic impression is AGC, it is important to consider MGL in the differential diagnosis.

A Simple Low-Cost Wearable Sensor for Long-Term Ambulatory Monitoring of Knee Joint Kinematics.

OBJECTIVE: Accurate monitoring of joint kinematics in individuals with neuromuscular and musculoskeletal disorders within ambulatory settings could provide important information about changes in disease status and the effectiveness of rehabilitation programs and/or pharmacological treatments. This paper introduces a reliable, power efficient, and low-cost wearable system designed for the long-term monitoring of joint kinematics in ambulatory settings. METHODS: Seventeen healthy subjects wore a retractable string sensor, fixed to two anchor points on the opposing segments of the knee joint, while walking at three different self-selected speeds. Joint angles were estimated from calibrated sensor values and their derivatives in a leave-one-subject-out cross validation manner using a random forest algorithm. RESULTS: The proposed system estimated knee flexion/extension angles with a root mean square error (RMSE) of 5.0°±1.0° across the study subjects upon removal of a single outlier subject. The outlier was likely a result of sensor miscalibration. CONCLUSION: The proposed wearable device can accurately estimate knee flexion/extension angles during locomotion at various walking speeds. SIGNIFICANCE: We believe that our novel wearable technology has great potential to enable joint kinematic monitoring in ambulatory settings and thus provide clinicians with an opportunity to closely monitor joint recovery, develop optimal, personalized rehabilitation programs, and ultimately maximize therapeutic outcomes.

Subjective expectations for future and mortality among middle-aged and older adults.

The purpose of this study is to categorize various elements for the expectations for the future using factor analysis and identify association between categories of the subjective expectations for the future and mortality among middle-aged and older adults.Data from the Korean Longitudinal Study of Aging from 2006 to 2016 was assessed using longitudinal data analysis and 9,844 research subjects were included at baseline in 2006. Our modeling approach was based on Cox proportional hazards models for mortality.We indicated 3 categories (individual factor, national factor, and combined factor) of 12 subjective expectations for the future using factor analysis. The negative expectations for the future of all factors [individual factor: hazard ratio (HR), 1.65, 95% confidence interval (CI), 1.41-1.93; national factor: HR, 1.20, 95% CI, 1.06-1.37; combined factor: HR, 1.16; 95% CI, 1.02-1.32] were more likely to have an increased risk of all-cause mortality than those in the positive expectations for the future. Older adults were more likely to be affected by negative expectations for the future in national factor compared to middle-aged adults (HR, 1.22; 95% CI, 1.05-1.41).Increasing positive expectations for the future is an important consideration for improvement in health. Policy makers need to consider that changes of national policy would affect health in older adults.

Comparative effectiveness of statins in secondary prevention among the older people aged 75 years and over.

Background While there is clear evidence for the benefit of statins in the secondary prevention of cardiovascular and cerebrovascular events, there is a lack of research on the effects of statin regimens in older patients aged 75 years and over. Objectives To compare the effectiveness of statin regimens in the secondary prevention of ischemic cardiovascular and cerebrovascular events among patients aged 75 years and over. Setting Claims data from the South Korean National Health Insurance Database from 2006 to 2014. Methods This retrospective cohort study included patients aged 75-100 years with a prior history of cardiovascular or cerebrovascular disease who began statin therapy in 2009-2011. Propensity score matching and the Cox proportional hazards regression model were used to compare the effectiveness of the statin regimens in secondary prevention. Main outcome measure The hazard ratios for ischemic cardiovascular and cerebrovascular events and all-cause mortality. Results Neither high nor low-intensity statin therapy significantly differed from moderate-intensity statin therapy in preventing ischemic cardiovascular and cerebrovascular events or all-cause mortality. Of the moderate-intensity statin therapies, the use of 10 mg rosuvastatin was more strongly associated with a reduced risk of ischemic cardiovascular and cerebrovascular events than was 10 mg atorvastatin [HR 0.79 (95% CI 0.64-0.98), p = 0.029]. Subgroup analysis revealed that the protective effects of 10 mg rosuvastatin against ischemic cardiovascular and cerebrovascular events were more obvious for patients who were 75-79 years old, those who were statin-adherent, those who did not have diabetes mellitus at baseline, and those who were non-adherent to aspirin or antiplatelet drugs during the selection and follow-up periods. Conclusion The results of this study support the preferential prescription of moderate-intensity rosuvastatin over moderate-intensity atorvastatin for the secondary prevention of ischemic cardiovascular and cerebrovascular events in older patients aged ≥ 75 years.

Association of nurse staffing grade and 30-day mortality in intensive care units among cardiovascular disease patients.

After the implementation of a policy differentiating inpatient nursing fees, no study is found in the nursing literature for intensive care unit (ICU) patients admitted with cardiovascular (CV) disease exclusively in Korea. This study investigates the relationship between ICU nurse staffing and 30-day mortality using large representative claim database.National Health Insurance Service-Senior (NHIS-Senior) claim database from 2002 to 2013, which was released by the Korean National Health Insurance Service (KNHIS), was used in this study. We included CV disease inpatients as a primary diagnostic code (I20-I25) who had their ICU utilization records from differentiating inpatient nursing fees code, resulting in 17,081 subjectsAfter adjusting for confounders, the hazard ratio (HR) for 30-day mortality after discharge (HR: 1.177; P: .018) and in-hospital 30-day mortality (HR: 1.145; P: .058) were higher in general hospital (GH) than in tertiary hospital (TH). In GH setting, HR for 30-day mortality after discharge (HR: 1.499; P: .010) and in-hospital 30-day mortality (HR: 1.377; P: .042) were higher in grade 7 to 9 than grade 1 to 2, but not in TH setting.This study shows that ICU nurse staffing related to improved mortality risk in GHs. Therefore, adequate nurse staffing to provide safe and high-quality care can be ensured by continuous monitoring and evaluation of nurse staffing.

Implementation of long-term care and hospital utilization: Results of segmented regression analysis of interrupted time series study.

This population-based time series study aimed to examine the effects of the long-term care insurance (LTCI) program on hospital utilization in Korea. Health insurance claim data and LTCI data were combined into a database of 92,596 individuals who were enrolled in Health Insurance at baseline. They were made of people who applied to LTCI program at least once since July 2008, and their hospital utilization records since 2002 were observed. Estimates of length of hospital stay (LOS) after the introduction of LTCI program were calculated using a segmented regression analysis. Although average LOS in hospitals implementation was lower pre-implementation period than post-implementation (16.865 days, SD: 4.864; 26.078 days, SD: 2.215, respectively, p < .0001), a decreasing trend was observed along the post-implementation period. The estimate for baseline trend, which reflect a trend in LOS before LTCI implementation, was 0.219 days (p < .0001). The estimate for Level change after intervention which is only indicated as the change of LOS was 2.821 days at the time of LTCI implementation, and was statistically significant (p < .0001). The estimate for Trend change after intervention, reflecting the trend in LOS after LTCI implementation, was -0.313, indicating a decreasing trend in LOS of -0.094 days (p = 0.0055), compared with the baseline trend. LTCI program was significantly associated with a decreasing trend in LOS. The results suggest that the introduction of LTCI program may have played a role in reducing LOS in older adults.

Association of Occupational Class with Healthcare Utilization among Economically Active Korean Adults from 2006 to 2014: A Repeated Cross-Sectional Study of Koreans Aged 19 Years and Older.

BACKGROUND: To investigate the impact of indicators of occupational class on healthcare utilization by using longitudinal data from a nationally representative survey. METHODS: Data were obtained from the Korean Welfare Panel Study conducted from 2006 (wave 1) through 2014 (wave 9). A total of 5,104 individuals were selected at baseline (2006). Analysis of variance and longitudinal data analysis were used to evaluate the following dependent variables: number of outpatient visits and number of days spent in the hospital per year. RESULTS: The number of annual outpatient visits was 4.298 days higher (P<0.0001) in class IV, 0.438 days higher (P=0.027) in class III, and 0.335 days higher (P=0.035) in class II than in class I. The number of days spent in the hospital per year was 0.610 days higher (P=0.001) in class IV, 0.547 days higher (P<0.0001) in class III, and 0.115 days higher (P=0.136) in class III than in class I. In addition, the number of days spent in the hospital in class IV patients with unmet healthcare needs showed an opposite trend to that predicted on the basis of socioeconomic status (estimate,-8.524; P-value=0.015). CONCLUSION: Patients whose jobs involved manual or physical labor were significantly associated with higher healthcare utilization. Thus, the results suggest that healthcare utilization in different occupational classes should be improved by monitoring work environments and promoting health-enhancing behaviors.

Assessment of colon polyp morphology: Is education effective?

AIM: To determine the inter-observer variability for colon polyp morphology and to identify whether education can improve agreement among observers. METHODS: For purposes of the tests, we recorded colonoscopy video clips that included scenes visualizing the polyps. A total of 15 endoscopists and 15 nurses participated in the study. Participants watched 60 video clips of the polyp morphology scenes and then estimated polyp morphology (pre-test). After education for 20 min, participants performed a second test in which the order of 60 video clips was changed (post-test). To determine if the effectiveness of education was sustained, four months later, a third, follow-up test was performed with the same participants. RESULTS: The overall Fleiss' kappa value of the inter-observer agreement was 0.510 in the pre-test, 0.618 in the post-test, and 0.580 in the follow-up test. The overall diagnostic accuracy of the estimation for polyp morphology in the pre-, post-, and follow-up tests was 0.662, 0.797, and 0.761, respectively. After education, the inter-observer agreement and diagnostic accuracy of all participants improved. However, after four months, the inter-observer agreement and diagnostic accuracy of expert groups were markedly decreased, and those of beginner and nurse groups remained similar to pre-test levels. CONCLUSION: The education program used in this study can improve inter-observer agreement and diagnostic accuracy in assessing the morphology of colon polyps; it is especially effective when first learning endoscopy.

Current globalization of drug interventional clinical trials: characteristics and associated factors, 2011-2013.

BACKGROUND: Clinical trial globalization is a major trend for industry-sponsored clinical trials. There has been a shift in clinical trial sites towards emerging regions of Eastern Europe, Latin America, Asia, the Middle East, and Africa. Our study objectives were to evaluate the current characteristics of clinical trials and to find out the associated multiple factors which could explain clinical trial globalization and its implications for clinical trial globalization in 2011-2013. METHODS: The data elements of "phase," "recruitment status," "type of sponsor," "age groups," and "design of trial" from 30 countries were extracted from the ClinicalTrials.gov website. Ten continental representative countries including the USA were selected and the design elements were compared to those of the USA. Factors associated with trial site distribution were chosen for a multilinear regression analysis. RESULTS: The USA, Germany, France, Canada, and United Kingdom were the "top five" countries which frequently held clinical trials. The design elements from nine continental representative countries were quite different from those of the USA; phase 1 trials were more prevalent in India (OR 1.517, p < 0.001) while phase 3 trials were much more prevalent in all nine representative countries than in the USA. A larger number of "child" age group trials was performed in Poland (OR 1.852, p < 0.001), Israel (OR 1.546, p = 0.005), and South Africa (OR 1.963, p < 0.001) than in the USA. Multivariate analysis showed that health care expenditure per capita, Economic Freedom Index, Human Capital Index, and Intellectual Property Rights Index could explain the variance of regional distribution of clinical trials by 63.6%. CONCLUSIONS: The globalization of clinical trials in the emerging regions of Asia, South Africa, and Eastern Europe developed in parallel with the factors of economic drive, population for recruitment, and regulatory constraints.

The impact of differences between subjective and objective social class on life satisfaction among the Korean population in early old age: Analysis of Korean longitudinal study on aging.

BACKGROUND: Several previous studies have established the relationship between the effects of socioeconomic status or subjective social strata on life satisfaction. However, no previous study has examined the relationship between social class and life satisfaction in terms of a disparity between subjective and objective social status. OBJECTIVE: To investigate the relationship between differences in subjective and objective social class and life satisfaction. METHODS: Data from the Korean Longitudinal Study of Aging with 8252 participants aged 45 or older was used. Life satisfaction was measured by the question, "How satisfied are you with your quality of life?" The main independent variable was differences in objective (income and education) and subjective social class, which was classified according to nine categories (ranging from high-high to low-low). This association was investigated by linear mixed model due to two waves data nested within individuals. RESULTS: Lower social class (income, education, subjective social class) was associated with dissatisfaction. The impact of objective and subjective social class on life satisfaction varied according to the level of differences in objective and subjective social class. Namely, an individual's life satisfaction declined as objective social classes decreased at the same level of subjective social class (i.e., HH, MH, LH). In both dimensions of objective social class (education and income), an individual's life satisfaction declined as subjective social class decreased by one level (i.e., HH, HM, HL). CONCLUSION: Our findings indicated that social supports is needed to improve the life satisfaction among the population aged 45 or more with low social class. The government should place increased focus on policies that encourage not only the life satisfaction of the Korean elderly with low objective social class, but also subjective social class.

Influence of Social Engagement on Mortality in Korea: Analysis of the Korean Longitudinal Study of Aging (2006-2012).

The objective of this study was to investigate the impact of social engagement and patterns of change in social engagement over time on mortality in a large population, aged 45 years or older. Data from the Korean Longitudinal Study of Aging from 2006 and 2012 were assessed using longitudinal data analysis. We included 8,234 research subjects at baseline (2006). The primary analysis was based on Cox proportional hazards models to examine our hypothesis. The hazard ratio of all-cause mortality for the lowest level of social engagement was 1.841-times higher (P < 0.001) compared with the highest level of social engagement. Subgroup analysis results by gender showed a similar trend. A six-class linear solution fit the data best, and class 1 (the lowest level of social engagement class, 7.6% of the sample) was significantly related to the highest mortality (HR: 4.780, P < 0.001). Our results provide scientific insight on the effects of the specificity of the level of social engagement and changes in social engagement on all-cause mortality in current practice, which are important for all-cause mortality risk. Therefore, protection from all-cause mortality may depend on avoidance of constant low-levels of social engagement.

Impact of health insurance status changes on healthcare utilisation patterns: a longitudinal cohort study in South Korea.

OBJECTIVES: The study examined medical care utilisation by health insurance status changes. SETTING: The Korean Welfare Panel Study (KoWePs) was used. PARTICIPANTS: This study analysed 14,267 participants at baseline (2006). INTERVENTIONS: The individuals were categorised into four health insurance status groups: continuous health insurance, change from health insurance to Medical Aid, change from Medical Aid to health insurance, or continuous Medical Aid. PRIMARY AND SECONDARY OUTCOME MEASURES: Three dependent variables were also analysed: days spent in hospital; number of outpatient visits; and hospitalisations per year. Longitudinal data analysis was used to determine whether changes in health insurance status were associated with healthcare utilisation. RESULTS: The number of outpatient visits per year was 0.1.363 times higher (p<0.0001) in the continuous Medical Aid than in the continuous health insurance group. The number of hospitalisations per year was 1.560 times higher (p<0.001) in new Medical Aid and -0.636 times lower (p<0.001) in new health insurance than in continuous health insurance group. The number of days spent in hospital per year was -0.567 times lower (p=0.021) in the new health insurance than in the continuous health insurance group. CONCLUSIONS: Health insurance beneficiaries with a coverage level lower than Medical Aid showed lower healthcare utilisation, as measured by the number of hospitalisations and days spent in hospital per year.

Having Private Cancer Insurance in Korea: Gender Differences.

BACKGROUND: As coverage of public insurance is not sufficient to cover diagnosis or treatment of cancer, having private health insurance is important to prepare for unexpected expenses of cancer. The purpose of this study was to assess factors associated with having private cancer insurance, considering gender among the socio- demographic factors and health behavior. MATERIALS AND METHODS: We used data from the 2011 Korea Health Panel, which included 10,871 participants aged 20 years and older. Socio-demographics, health behavior, and perceived cancer risk were the independent variables and having private cancer insurance was the dependent variable. Multivariable logistic regression analysis was used to identify factors associated with having private cancer insurance. RESULTS: The variables relating to middle age, higher education, higher household income, married men, and the perceived cancer risk groups of 1-10% and 11-30% were significantly associated with having private cancer insurance. Additionally, females who had private non-cancer health insurance were positively associated with the dependent variables (OR=1.36; 95% CI=1.17-1.57). Education, smoking status, exercise, and perceived cancer risk possibility were significantly associated with having private cancer insurance only among women. The men lowered the overall percentages of those having private cancer insurance (OR=0.53, 95% CI=0.45-0.63). CONCLUSIONS: We found that there were significant differences between men and women who had private cancer insurance. Women with private cancer insurance are more likely to follow precautionary health behavior than men. This could be interpreted as resulting from masculine ideologies. It is important to make males recognize the seriousness of the cancer risk. In general, household income was highly associated with private cancer insurance. These results reveal an inequity among the buyers of private cancer insurance in terms of economic status level, education level, and health condition.