[Health inequalities in Korea: current conditions and implications]

Analysis of Major Factors Affecting the Quality of Life of the Elderly in Korea in Preparation for a Super-Aged Society

In preparation for the expected super-aged society in 2025, this study attempted to prepare basic data that can help design development measures for the welfare of the elderly so that everyone can prepare for a healthy and happy retirement. Accordingly, the major factors affecting the quality of life of the elderly in Korea were verified. To this end, the questionnaire consisted of 22 questions in total, and a mobile survey was conducted between September and October 2021; in total, 250 copies were used for the final analysis, and the following conclusions are derived. The major factors that were found to determine the quality of life of the elderly were age, subjective health status, monthly household income, leisure activities, and health inequality fairness. It was found that the higher the age, the lower the quality of life. Further, the higher the subjective health status, monthly household income, participation in leisure activities, and perceptions of health inequality as fair, the more the quality of life of the elderly was affected. Therefore, policy support such as leisure activity, health programs, and medical welfare services for the elderly and sufficient attention from our society are all required.

Analysis of energy intakes, physical activities and metabolic syndrome according to the income level in Korean elderly people: Korean National Health and Nutrition Examination Survey 2016‒2018

[Purpose]

To determine the correlations of differences in the income level with the presence of metabolic syndrome (MetS), energy intake, and physical activity across Korean elderly populations.

[Methods]

We obtained data from 2,139 elderly individuals (aged >65 years) based on the Korea National Health and Nutrition Examination Survey (KNHANES) (2016‒2018). We analyzed the levels of physical activity (PA) and energy intake using the survey data. Moreover, we analyzed the differences in energy intake and PA levels according to the income level and MetS.

[Results]

Compared with the non-MetS group, the MetS group displayed significantly higher levels of waist circumference (p=0.000), triglycerides (p=0.000), systolic blood pressure (p=0.000), diastolic blood pressure (p=0.016), and fasting blood glucose (p=0.000) for both high and low income levels. However, the level of high-density lipoprotein cholesterol was significantly lower in the MetS group than that in the non-MetS group (p=0.000). The level of smoking in non-MetS men was significantly higher than that in MetS men across all participants (p=0.047). Except carbohydrate intake, the total energy intake (p=0.022), fat intake (p=0.009), and protein intake (p=0.005) were significantly lower in the MetS group than those in the non-MetS group for high income levels. We obtained similar results for low income levels. The two-way analysis of variance (ANOVA) did not identify an interaction between the income level and the presence of MetS; however, the total energy, i.e., the level of total energy intake, was significantly lower in participants with low income levels than in those with high income levels. For high income levels, transport PA (p=0.002), vigorous recreational PA (p=0.001), moderate recreational PA (p=0.001), and total PA (p=0.000) were significantly lower in the MetS group than those in the non-MetS group. For low income levels, moderate occupational PA (p=0.012), transport PA (p=0.018), and total PA ((p=0.000) were significantly lower in the MetS group than those in the non-MetS group. The total PA, i.e., the level of energy consumption, was significantly lower in the elderly with low income levels than in those with high income levels.

[Conclusion]

Regardless of the income level, the elderly with MetS exhibited low levels of energy intake and PA, compared with those without MetS. In addition, regardless of the presence of MetS, the elderly with low income levels exhibited lesser energy intake and PA. These findings implied the need for balanced nutrient intake and increased participation in PA as well as education and program development to prevent MetS in the elderly.

Effect of socioeconomic deprivation on outcomes of diabetes complications in patients with type 2 diabetes mellitus: a nationwide population-based cohort study of South Korea

INTRODUCTION

This study aimed to examine the effect of socioeconomic deprivation on the outcomes of diabetes complications in patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We conducted a cohort study using claims data and 2005 national census data. We included of 7510 patients newly diagnosed with T2DM from 2004 to 2012 and aged 40 years or above. We excluded participants who had onset of diabetes complications and hospitalization within 1 year after initial onset T2DM, aged less than 40 years and with missing covariates. We used the regional socioeconomic deprivation index and classified study participants into five categories according to the quintile distribution. We calculated the adjusted HR and 95% CI for hospitalization related to diabetes complications and all-cause mortality by applying Cox proportional hazards model and the adjusted subdistribution hazards model.

RESULTS

The percentages of participants in the first quintile (least deprived) to fifth quintile (most deprived) were 27.0%, 27.9%, 19.5%, 14.8%, and 10.8% for socioeconomic deprivation; 25.4%, 28.8%, 32.4%, 34.6%, and 37.6% for hospitalization due to diabetes complications; 1.3%, 2.1%, 2.5%, 2.9%, and 3.6% for deaths from diabetes complications; and 5.7%, 7.2%, 9.7%, 9.7%, and 13.1% for deaths from all causes, respectively. Participants with higher socioeconomic deprivation had a higher HR for hospitalization and mortality from all-cause and diabetes complications. These associations were the strongest among men and participants in their 40s in hospitalization related to diabetes complications, 50s in diabetes complications-specific mortality and 50s and 60s in all-cause mortality.

CONCLUSIONS

Patients with T2DM with high socioeconomic deprivation had higher hospital admission and mortality rates for diabetes complications than those with low deprivation. We cannot fully explain the effect of socioeconomic deprivation on diabetes outcomes. Therefore, further studies are needed in order to find underlying mechanisms for these associations.

Interactions between Ambient Air Particles and Greenness on Cause-specific Mortality in Seven Korean Metropolitan Cities, 2008-2016

This study aims to investigate the association of particulate matter with an aerodynamic diameter smaller than 10 μm (PM₁₀) and greenness with cause-specific mortality and their interactions in seven Korean metropolitan cities. We obtained the annual standardized cause-specific mortality rates, annual mean concentration of PM₁₀, and annual Normalized Difference Vegetation Index (NDVI) for 73 districts for the period 2008-2016. We used negative binomial regression with city-specific random effects to estimate the association of PM₁₀ and greenness with mortality. The models were adjusted for potential confounders and spatial autocorrelation. We also conducted stratified analyses to investigate whether the association between PM₁₀ and mortality differs by the level of greenness. Our findings suggest an increased risk of all causes examined, except respiratory disease mortality, with high levels of PM₁₀ and decreased risk of cardiovascular-related mortality with a high level of greenness. In the stratified analyses, we found interactions between PM₁₀ and greenness, but these interactions in the opposite direction depend on the cause of death. The effects of PM₁₀ on cardiovascular-related mortality were attenuated in greener areas, whereas the effects of PM₁₀ on non-accidental mortality were attenuated in less green areas. Further studies are needed to explore the underlying mechanisms.

The Association between Socioeconomic Status and Adherence to Health Check-up in Korean Adults, Based on the 2010-2012 Korean National Health and Nutrition Examination Survey

Background

We investigated the association between socioeconomic status and adherence to health check-ups in a Korean population aged 40 years or older.

Methods

This cross-sectional study included 12,311 participants who participated in the 2010–2012 Korean National Health and Nutrition Examination Survey. Self-reported questionnaires were used to assess each participant's socioeconomic status (household income, occupation, and education) and adherence to health check-ups.

Results

Men with a higher income (highest vs. lowest: odds ratio [OR], 1.799; 95% confidence interval [CI], 1.296–2.497) and men with a higher education level (≥12 vs. <6 years: OR, 1.488; 95% CI, 1.078–2.054) and office workers compared with manual workers (men: OR, 1.431; 95% CI, 1.077–1.902; women: OR, 1.783; 95% CI, 1.256–2.532) appeared to undergo more health check-ups. In particular, men and women with a higher income and education appeared more likely to undergo opportunistic health check-ups (men: highest vs. lowest income: OR, 2.380; 95% CI, 1.218–4.653; ≥12 vs. <6 years education: OR, 2.121; 95% CI, 1.142–3.936; women: highest vs. lowest income: OR, 4.042; 95% CI, 2.239–7.297; ≥12 vs. <6 years education: OR, 2.475; 95% CI, 1.283–4.775).

Conclusion

A higher socioeconomic status was associated with a higher rate of participation in health check-ups. More efforts are needed to identify the factors associated with disparity in adherence to health check-ups.

Recent Trends in Blood Pressure According to Economic Status: Korean National Health and Nutrition Examination Survey From 2005 to 2015

Our study assessed recent blood pressure (BP) trends according to economic status based on data from 2005 to 2015. In total, 56 873 participants were included and were defined as low, middle-low, middle-high, and high according to their house income quartile. In men, the mean systolic BP ( P < .001, β = −1.95; P = .01, β = −0.61; P = .35, β = −0.19; and P = .04, β = −0.47, from the low to the high group, respectively) and diastolic BP were decreased significantly in all groups ( P < .001, β = −2.18; P < .001, β = −0.77; P = .02, β = −0.40; and P < .001, β = −0.69, from the low to the high group, respectively). In women, the decreasing trends in systolic BP and diastolic BP were statistically significant except in the high-income group. In addition, the percentages of less-than-normotensive and less-than-hypertensive BP in both sexes and the control rate of hypertension on antihypertensive medications increased in all groups. Decreasing BP trends were observed in the recent decade and the gap in health inequities has been decreased, particularly in men in Korea.

Health inequalities in hypertension and diabetes management among the poor in urban areas: a population survey analysis in south Korea

BACKGROUND

This study investigated whether the prevalence, awareness, treatment, and control of hypertension and diabetes differed by residential areas. In addition, the rate of good hypertension or diabetes control was examined separately in men and women, and in urban and rural areas.

METHODS

This study used Korea National Health and Nutrition Examination V (2010-2012) data, a nationwide cross-sectional survey of general South Korean population. Residential areas were categorized into urban and rural areas. To examine differences between the residential areas in terms of prevalence, awareness, treatment, and control of hypertension and diabetes we performed a multivariate logistic regression adjusting for age, body mass index, physical activity, alcohol use, smoking, marital status, monthly income, and educational level. To investigate control of hypertension or diabetes within each residential area, we performed a subgroup analysis in both urban and rural areas.

RESULTS

The prevalence of hypertension is higher among men in urban areas than among those in rural areas (OR = 0.80; 95 % CI = 0.67-0.96, reference group = urban areas). However, the subgroups did not differ in terms of diabetes prevalence, awareness, treatment, and control. Regardless of both sex and residential area, participants in good control of their hypertension and diabetes were younger. Inequality in good control of hypertension was observed in men who lived in urban (≤Elementary school, OR 0.74, 95 % CI 0.60-0.92) and rural areas (≤Elementary school, OR 0.67, 95 % CI 0.46-0.99). Inequality in health status was found in women who resided in urban areas (≤Elementary school, OR 0.53, 95 % CI 0.37-0.75). Good control of diabetes also showed inequalities in health status for both men (≤Elementary school, OR 0.61, 95 % CI 0.40-0.94; Middle/High school, OR 0.69, 95 % CI 0.49-0.96) and women in urban areas (≤1 million won, OR 0.56, 95 % CI 0.33-0.93) (Reference group = '≥College' for education and '>3 million' Korean won for income).

CONCLUSIONS

After correction for individual socioeconomic status, differences by residential area were not observed. However, when the participants with good disease control were divided by region, inequality was confirmed in urban residents. Therefore, differentiated health policies to resolve individual and regional health inequalities are necessary.

Socioeconomic Inequality in mortality using 12-year follow-up data from nationally representative surveys in South Korea

Background

Investigations into socioeconomic inequalities in mortality have rarely used long-term mortality follow-up data from nationally representative samples in Asian countries. A limited subset of indicators for socioeconomic position was employed in prior studies on socioeconomic inequalities in mortality. We examined socioeconomic inequalities in mortality using follow-up 12-year mortality data from nationally representative samples of South Koreans.

Methods

A total of 10,137 individuals who took part in the 1998 and 2001 Korea National Health and Nutrition Examination Surveys were linked to mortality data from Statistics Korea. Of those individuals, 1,219 (12.1 %) had died as of December 2012. Cox proportional hazard models were used to estimate the relative risks of mortality according to a wide range of socioeconomic position (SEP) indicators after taking into account primary sampling units, stratification, and sample weights.

Results

Our analysis showed strong evidence that individuals with disadvantaged SEP indicators had greater all-cause mortality risks than their counterparts. The magnitude of the association varied according to gender, age group, and specific SEP indicators. Cause-specific analyses using equivalized income quintiles showed that the magnitude of mortality inequalities tended to be greater for cardiovascular disease and external causes than for cancer.

Conclusion

Inequalities in mortality exist in every aspect of SEP indicators, both genders, and age groups, and four broad causes of deaths. The South Korean economic development, previously described as effective in both economic growth and relatively equitable income distribution, should be scrutinized regarding its impact on socioeconomic mortality inequalities. Policy measures to reduce inequalities in mortality should be implemented in South Korea.

Electronic supplementary material

The online version of this article (doi:10.1186/s12939-016-0341-9) contains supplementary material, which is available to authorized users.

Physical activity disparities by socioeconomic status among metabolic syndrome patients: The Fifth Korea National Health and Nutrition Examination Survey

Physical activity plays an important role in preventing further progression of metabolic syndrome conditions to cardiovascular disease and type-2 diabetes. This study investigated physical activity disparities by socioeconomic status among metabolic syndrome patients. The fifth Korea National Health and Nutrition Examination Survey (2010–2012) data were analyzed (n=19,831). A revised definition of the US National Cholesterol Education Program Adult Treatment Panel III was used for screening metabolic syndrome patients. Using International Physical Activity Questionnaire, physical activity adherence was defined as participating in 150+ minutes of moderate-intensity physical activity, 75+ minutes of vigorous-intensity physical activity, or an equivalent combination of moderate-to vigorous-intensity physical activity per week. Socioeconomic status was measured by level of education and house-hold income. Among metabolic syndrome patients, physical activity adherence rate of first (lowest), second, third, and fourth quartile house-hold income group were 28.31% (95% confidence interval [CI], 26.14–30.28%), 34.68% (95% CI, 32.71–36.70), 37.44% (95% CI, 35.66–39.25), and 43.79% (95% CI, 41.85–45.75). Physical activity adherence rate of groups with elementary or lower, middle-school, high-school, and college or higher education degree were 25.17% (95% CI, 22.95–27.54), 38.2% (95% CI, 35.13–41.00), 39.60% (95% CI, 38.24–41.77), and 36.89% (95% CI, 35.77–38.03), respectively. This study found that physical activity adherence rate was lower in socioeconomically disadvantaged metabolic syndrome patients, which may aggravate health inequity status of Korean society.

Trend of Suicide Rates According to Urbanity among Adolescents by Gender and Suicide Method in Korea, 1997-2012

This study aims to quantifiably evaluate the trend of the suicide rate among Korean adolescents from 1997 to 2012 according to urbanity. We used national death certificates and registration population data by administrative district for 15–19 years-old adolescents. The annual percent change (APC) and average annual percent change (AAPC) were estimated by the Joinpoint Regression Program. The suicide rate in the rural areas was higher than that in the urban areas in both genders (males (/100,000), 12.2 vs. 8.5; females (/100,000), 10.2 vs. 7.4 in 2012). However, the trend significantly increased only in the urban area (AAPC [95% CI]: males 2.6 [0.7, 4.6], females 3.3 [1.4, 5.2]). In urban areas, the suicide rate by jumping significantly increased in both genders (AAPC [95% CI]: males, 6.7 [4.3, 9.1]; females, 4.5 [3.0, 6.1]). In rural areas, the rate by self-poisoning significantly decreased by 7.9% per year for males (95% CI: −12.5, −3.0) and the rate by hanging significantly increased by 10.1% per year for females (95% CI: 2.6, 18.2). The trend and methods of suicide differ according to urbanity; therefore, a suicide prevention policy based on urbanity needs to be established for adolescents in Korea.

Working conditions and leisure-time physical activity among waged workers in South Korea: A cross-sectional study

OBJECTIVES

Although waged workers' working conditions have notably diversified in South Korea, there is little research addressing this issue. This study explores the relationship between working conditions and engagement in leisure-time physical activities (LTPA) among waged workers in South Korea.

METHODS

Data from 19- to 64-year-old waged workers (men=2,562, women=1,627) from the 11th wave of the Korean Income and Labor Panel Study were included in this study. Multiple logistic regression analyses were conducted to assess the association between LTPA and working conditions by gender.

RESULTS

More than 75% of employed persons did not participate in any type of LTPA. For male workers, those in manual, precarious, overtime, and non-shift positions were less likely to engage in LTPA, while for female workers, only manual and overtime work positions were significant factors influencing a low level of LTPA.

CONCLUSIONS

Some negative work-related factors were associated with low LTPA, especially for male workers. Further studies should be conducted to clarify the pathways and barriers precluding engagement in LTPA due to work-related factors.

Trends in income-related health inequalities in self-assessed health in Korea, 1998-2011

This study assesses income-related health inequalities in self-assessed health (SAH) and its trend from 1998 to 2011 in Korea that covers important time periods of financial crisis and post-crisis. Data came from the Korean National Health and Nutrition Examination Survey from 1998 to 2011. A population-representative sample aged 46 years and older was analysed. SAH was used as an indicator of health status, with household equivalence income as a proxy for socio-economic position. Age-adjusted prevalence rates of SAH were analysed to estimate both absolute and relative measures of health inequalities and the trend over time by the relative index of inequality (RII) and the slope index of inequality (SII). Results indicated that the highest level of health inequalities was found among men aged 46-59 years, especially in 2001 and 2005. For men, there was no clear, consistent pattern of increase or decrease in the trend over time. On the other hand, increasing trends in the RII and SII were found for women, except for women aged 46-59 years who reported a decreasing trend in the SII. Trends in health inequalities over time were influenced by economic crisis, demonstrating the need for macro-level economic policies as well as health policies addressing health gaps.

National screening program for transitional ages in Korea: a new screening for strengthening primary prevention and follow-up care

Screening can effectively reduce mortality and morbidity in some diseases. In Korea, a practical national screening program for chronic disease was launched in 1995 and several problems were discussed. The program focused primarily on disease detection without follow-up care. In addition, the test items were uniform regardless of subject's age, sex, or risk factors; and people with low socioeconomic status were excluded. To improve the quality of program, a new national screening program called the "National Screening Program for Transitional Ages (NSPTA)" was initiated in 2007. It targeted two age groups, ages 40 and 66, because these ages are important transition periods in one's lifecycle. Follow-up care and education for lifestyle modification has been intensified; screening tests for mental health problems and osteoporosis have been introduced. The pool of eligible participants has been expanded to include people supported by Medicaid. This review aimed to describe the contents, process, and characteristics of the NSPTA and to compare it with the previous program. In addition, some preliminary results from 2007 to 2009 were presented. Lastly, we suggest several points that need to be considered to improve the program such as enhancement of participation rates, necessity of specialized committee and research for current screening program to be supported by evidence.

Health inequalities policy in Korea: current status and future challenges

In recent years, health inequalities have become an important public health concern and the subject of both research and policy attention in Korea. Government reports, as well as many epidemiological studies, have provided evidence that a wide range of health outcomes and health-related behaviors are socioeconomically patterned, and that the magnitude of health inequalities is even increasing. However, except for the revised Health Plan 2010 targets for health equity, few government policies have explicitly addressed health inequalities. Although a number of economic and social policies may have had an impact on health inequalities, such impact has scarcely been evaluated. In this review, we describe the current status of research and policy on health inequalities in Korea. We also suggest future challenges of approaches and policies to reduce health inequalities and highlight the active and intensive engagement of many policy sectors and good evidence for interventions that will make meaningful reduction of health inequalities possible.

Health status and epidemiological capacity and prospects: WHO Western Pacific Region

BACKGROUND

This article on the state of epidemiology in the WHO Western Pacific Region (WPR) is the first in a series of eight articles commissioned by the International Epidemiological Association (IEA) to identify global opportunities to promote the development of epidemiology.

METHODS

Global mortality and disease data were used to summarize the burden of mortality, disease, risk factor and patterns of inequalities in the region. Medline bibliometrics were used to estimate epidemiological publication output by country. Key informant surveys, Internet and literature searches and author knowledge and networks were used to elicit perspectives on epidemiological training, research, funding and workforce. Findings The WPR has the lowest age-standardized disability-adjusted life-years (DALY) rate per 1000 of the six WHO regions, with non-communicable disease making the largest percentage contributions in both low- and middle-income countries (LMICs, 68%) and high-income countries (HICs, 84%) in the WPR. The number of Medline-indexed epidemiological research publications per year was greatest for Japan, Australia and China. However, the rate per head of population was greatest for Micronesia and New Zealand. The substantive focus of research roughly equated with burden of disease patterns. Research capacity (staff, funding, infrastructure) varies hugely between countries. Epidemiology training embedded within academic Masters of Public Health programmes is the dominant vehicle for training in most countries. Field epidemiology and in-service training are also common. The Pacific Island countries and territories, because of sparse populations over large distances and chronic workforce and funding capacity problems, rely on outside agencies (e.g. WHO, universities) for provision of training. Cross-national networks and collaborations are increasing.

CONCLUSION

Communicable disease surveillance and research need consolidation (especially in eastern Asian WPR countries), and non-communicable disease epidemiological capacity requires strengthening to match disease trends. Capacity and sustainability of both training and research within LMICs in WPR are ongoing priorities. China in particular is advancing quickly. One role for the IEA in building capacity is facilitating collaborative networks within WPR.

Income-related inequalities in the prevalence of depression and suicidal behaviour: a 10-year trend following economic crisis

The issue of health inequalities has steadily gained attention in South Korea, as income inequality widened and social polarization increased following the country's economic crisis in the late 1990s. While official figures indicate a general trend of worsening mental health, with rapidly rising rates of suicide and depression in particular, the extent of socio-economic inequality with respect to mental health problems has not been well elucidated. This study aimed to measure income-related inequalities in depression, suicidal ideation and suicide attempts in South Korea and to trace their changes over a 10-year period (1998-2007). The concentration index approach was employed to quantify the degree of income-related inequalities, using four waves of the Korea National Health and Nutrition Examination Survey data. The study found persistent pro-rich inequality in depression, suicidal ideation and suicide attempts over the past decade (i.e., individuals with higher incomes were less likely to have these conditions). The inequalities actually doubled over this period. These findings imply a need for expanded social protection policies for the less privileged in the population.

[Socioeconomic inequity in self-rated health status and contribution of health behavioral factors in Korea]

OBJECTIVES

The study is investigated socioeconomic variations in self-rated health status and contribution of health behavioral factors in Korea.

METHODS

A nationally representative sample (2,800 men and 3,230 women aged 20-64 years) from the 2005 Korea National Health and Nutrition Surveys was analyzed using logistic regression.

RESULTS

Self-rated health was lower among lower socioeconomic groups compared with higher socioeconomic groups, with gender being irrelevant. This association was attenuated when health behavioral and socio-demographic factors were adjusted. When each health behavioral factor was considered separately, mediators such as smoking in men, and stress or exercise in women explained a large part of the decreased socioeconomic health inequalities.

CONCLUSIONS

In Korea, subjective health inequalities arise from different socioeconomic status, but this difference is decreased by health behavioral factors. Therefore, socioeconomic inequity in self-rated health status can be corrected more effectively by promotional health behaviors.

[Analysis for the impact of adulthood and childhood socioeconomic positions and intergenerational social mobility on adulthood health]

OBJECTIVES

There are at least three conceptual models for the effects of the childhood social environment on adult health: the critical period model, the social mobility model, and the cumulative risk model. However, few studies have investigated all three different models within the same setting. This study aims to examine the impact of childhood and adulthood socioeconomic positions and intergenerational social mobility over the life course on the health in adulthood based both on the critical period model and the social mobility model.

METHODS

This study was conducted on 9583 adults aged between 25 and 64 years old and they were the respondents to the Korea Welfare Panel Study (2006). A multivariate logistic regression analysis was carried out, using the critical period model and the social mobility model out of the life course approaches, to look into the impact of childhood and adulthood socioeconomic positions and intergenerational social mobility on the health status in adulthood.

RESULTS

Household income and occupation out of the adulthood socioeconomic position indicators had an independent influence on the adulthood health status. The childhood socioeconomic position indicators, except for the place of childhood residence, affected the adulthood health status even after adjustment for the adulthood socioeconomic position. The effect of intergenerational social mobility was also statistically significant even after adjusting for the adulthood socioeconomic position, but it became insignificant when the childhood socioeconomic position was additionally adjusted for.

CONCLUSIONS

Adulthood health is indeed affected by both the childhood and adulthood socioeconomic positions as well as intergenerational social mobility. This result shows that a life course approach needs to be adopted when dealing with health issues.