Forty years of economic growth and plummeting mortality: the mortality experience of the poorly educated in South Korea

Educational inequalities in adult mortality: a systematic review and meta-analysis of the Asia Pacific region

OBJECTIVES

In this study, we aim to analyse the relationship between educational attainment and all-cause mortality of adults in the high-income Asia Pacific region.

DESIGN

This study is a comprehensive systematic review and meta-analysis with no language restrictions on searches. Included articles were assessed for study quality and risk of bias using the Joanna Briggs Institute critical appraisal checklists. A random-effects meta-analysis was conducted to evaluate the overall effect of individual level educational attainment on all-cause mortality.

SETTING

The high-income Asia Pacific Region consisting of Japan, South Korea, Singapore and Brunei Darussalam.

PARTICIPANTS

Articles reporting adult all-cause mortality by individual-level education were obtained through searches conducted from 25 November 2019 to 6 December 2019 of the following databases: PubMed, Web of Science, Scopus, EMBASE, Global Health (CAB), EconLit and Sociology Source Ultimate.

PRIMARY AND SECONDARY OUTCOME MEASURES

Adult all-cause mortality was the primary outcome of interest.

RESULTS

Literature searches resulted in 15 345 sources screened for inclusion. A total of 30 articles meeting inclusion criteria with data from the region were included for this review. Individual-level data from 7 studies covering 222 241 individuals were included in the meta-analyses. Results from the meta-analyses showed an overall risk ratio of 2.40 (95% CI 1.74 to 3.31) for primary education and an estimate of 1.29 (95% CI 1.08 to 1.54) for secondary education compared with tertiary education.

CONCLUSION

The results indicate that lower educational attainment is associated with an increase in the risk of all-cause mortality for adults in the high-income Asia Pacific region. This study offers empirical support for the development of policies to reduce health disparities across the educational gradient and universal access to all levels of education.

PROSPERO REGISTRATION NUMBER

CRD42020183923.

What have we learned about mortality patterns over the past 25 years?

In this paper, I examine progress in the field of mortality over the past 25 years. I argue that we have been most successful in taking advantage of an increasingly data-rich environment to improve aggregate mortality models and test pre-existing theories. Less progress has been made in relating our estimates of mortality risk at the individual level to broader mortality patterns at the population level while appropriately accounting for contextual differences and compositional change. Overall, I find that the field of mortality continues to be highly visible in demographic journals, including Population Studies. However much of what is published today in field journals could just as easily appear in neighbouring disciplinary journals, as disciplinary boundaries are shrinking.

Analysis of factors contributing to occupational health inequality in Korea: a cross-sectional study using nationally representative survey data

Background

Despite the consensus that higher occupational classes tend to have better health and lower mortality rates, one study has reported reversed occupational gradients in mortality rates among Korean men after the economic crisis in the late 2000s. To examine these patterns of health inequality in more detail, we investigated the tendency of occupational gradients in socioeconomic position and multiple pathway indicators known to affect mortality in Korea.

Methods

We used data from 4176 men aged 35–64 in Korea derived from the 2007–2009 and 2013–2015 Korean National Health and Nutrition Examination Surveys. We compared the age-standardized prevalence and age-adjusted mean values of each contributing factor to health inequality among occupational groups, which are divided into upper non-manual workers, lower non-manual workers, manual workers, and others. Contributing factors included childhood and adulthood socioeconomic position indicators, biological risk factors, health behaviors, psychosocial factors, and work environment.

Results

Upper non-manual workers had prominently higher levels of education, income, parental education, and economic activity than lower non-manual and manual workers. The rates of smoking and high-risk alcohol consumption were lower, and the rate of weight control activities was higher, in the non-manual classes. Further, the rates of depression and suicidal ideation were lower, and perceptions of the work environment were more favorable, among non-manual workers than among their manual counterparts.

Conclusions

We detected occupational inequality in a wide range of socioeconomic positions and pathway indicators in Korea with consistently favorable patterns for upper non-manual workers. These occupational gradients do not support the previously reported reversed pattern of higher mortality rates in non-manual groups versus in the manual job class in Korea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00638-9.

Spatio-temporal Analysis of District-level Life Expectancy from 2004 to 2017 in Korea

BACKGROUND

Health indicators, such as mortality rates or life expectancy, need to be presented at the local level to improve the health of local residents and to reduce health inequality across geographic areas. The aim of this study was to estimate life expectancy at the district level in Korea through a spatio-temporal analysis.

METHODS

Spatio-temporal models were applied to the National Health Information Database of the National Health Insurance Service to estimate the mortality rates for 19 age groups in 250 districts from 2004 to 2017 by gender in Korea. Annual district-level life tables by gender were constructed using the estimated mortality rates, and then annual district-level life expectancy by gender was estimated using the life table method and the Kannisto-Thatcher method. The annual district-level life expectancies based on the spatio-temporal models were compared to the life expectancies calculated under the assumption that the mortality rates in these 250 districts are independent from one another.

RESULTS

In 2017, district-level life expectancy at birth ranged from 75.5 years (95% credible interval [CI], 74.0-77.0 years) to 84.2 years (95% CI, 83.4-85.0 years) for men and from 83.9 years (95% CI, 83.2-84.6 years) to 88.2 years (95% CI, 87.3-89.1 years) for women. Between 2004 and 2017, district-level life expectancy at birth increased by 4.57 years (95% CI, 4.49-4.65 years) for men and by 4.06 years (95% CI, 3.99-4.12 years) for women. To obtain stable annual life expectancy estimates at the district level, it is recommended to use the life expectancy based on spatio-temporal models instead of calculating life expectancy using observed mortality.

CONCLUSION

In this study, we estimated the annual district-level life expectancy from 2004 to 2017 in Korea by gender using a spatio-temporal model. Local governments could use annual district-level life expectancy estimates as a performance indicator of health policies to improve the health of local residents. The approach to district-level analysis with spatio-temporal modeling employed in this study could be used in future analyses to produce district-level health-related indicators in Korea.

Educational Inequalities in Self-Rated Health in Europe and South Korea

While numerous comparative works on the magnitude of health inequalities in Europe have been conducted, there is a paucity of research that encompasses non-European nations such as Asian countries. This study was conducted to compare Europe and Korea in terms of educational health inequalities, with poor self-rated health (SRH) as the outcome variable. The European Union Statistics on Income and Living Conditions and the Korea National Health and Nutrition Examination Survey in 2017 were used (31 countries). Adult men and women aged 20+ years were included (207,245 men and 238,007 women). The age-standardized, sex-specific prevalence of poor SRH by educational level was computed. The slope index of inequality (SII) and relative index of inequality (RII) were calculated. The prevalence of poor SRH was higher in Korea than in other countries for both low/middle- and highly educated individuals. Among highly educated Koreans, the proportion of less healthy women was higher than that of less healthy men. Korea’s SII was the highest for men (15.7%) and the ninth-highest for women (10.4%). In contrast, Korea’s RII was the third-lowest for men (3.27), and the lowest among women (1.98). This high-SII–low-RII mix seems to have been generated by the high level of baseline poor SRH.

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

BACKGROUND

This study compared inequalities in the longitudinal trajectory of health measured by latent growth curves (LGCs) in Korea and six other developed European countries.

METHODS

Unconditional and conditional LGCs were fitted, with standardized self-rated health (SRH) as the outcome variable. Two nationally-representative longitudinal datasets were used: the Survey of Health, Aging and Retirement in Europe (2007-2015; 2,761 Swedish, 2,546 Danish, 2,580 German, 2,860 French, 2,372 Spanish, and 2,924 Italian respondents) and the Korean Longitudinal Study of Aging (2006-2014; 8,465 Korean respondents).

RESULTS

The unconditional patterns of SRH trajectory were similar and unfavorable for women across the countries. Social factors such as education and income generally exerted a significant impact on health trends among older adults. Korea showed less favorable results for the disadvantaged than the advantaged as compared with Denmark, Germany, and France, which was consistent with theoretical expectations. In contrast, the relative SRH trajectory of the disadvantaged as against the advantaged was better as compared with Sweden and worse as compared with Spain/Italy, which was inconsistent with theories that would predict Korea's results were worse than Sweden and similar to Spain/Italy. Women had good SRH trajectory in Denmark and poorer SRH trajectory in Spain, Italy, and Korea, which were consistent. However, women in Sweden showed poorer and mixed outcome, which does not correspond to theoretical predictions.

CONCLUSION

These findings suggest that it is inconclusive whether Sweden and Denmark (with the most generous welfare arrangements) have better trajectories of health, and Spain, Italy, and Korea (with the least advanced state policies) have worse SRH paths among older adults. However, it can be inferred that Korean governmental policies may have produced a relatively worse context for the less-educated than the six European countries, as well as poorer settings for women than Denmark in terms of their initial SRH status.

Socioeconomic disparities in self-rated health in two East Asian countries: Comparative study between Japan and Korea

Although Japan and South Korea share a number of commonalities, social security systems are very different. We opt to compare socioeconomic disparities in self-rated health between these two countries. The analytic sample included those aged 20 years and older from the nationally representative surveys in Japan (Comprehensive Survey of Living Conditions) and South Korea (Korean Community Health Survey). As socioeconomic status, we used income (quintiles of equivalized annual household income) and education (five categories). We measured socioeconomic inequalities using two indices; the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII), in each age group for each country. In Japan, we found relatively little evidence of socioeconomic inequalities in self-rated health over the life course, on either the absolute or relative scale. In Korea, the absolute inequality assessed by SII of self-rated poor health was higher in middle and old age groups compared to other age groups, while relative inequality measured by RII was significantly higher in younger ages. In Japan with more generous welfare system to the older generations, health inequality was relatively lower compared to Korea. The gaps in health status for Korean people suggest where social policy might direct their efforts in the future - (a) reducing inequalities in working-age people by addressing the gap between standard workers & non-standard workers; and (b) improving the financial conditions of older people by shoring up the social security system.

Avoidable, amenable, and preventable mortalities in South Korea, 2000-2017: Age-period-cohort trends and impact on life expectancy at birth

This study aimed to estimate age-period-cohort effects on avoidable mortality and quantify the impact of avoidable mortality changes on life expectancy (LE) at birth in the South Korean population aged 0-74 years. Using death certificate and resident population data from 2000 to 2017, trends in age-standardized avoidable mortality rates were analyzed with joinpoint regression. Intrinsic estimator regression analysis was conducted to estimate age-period-cohort effects on avoidable mortality. Arriaga's method was used to measure the contributions of avoidable causes to changes in LE gaps between adjacent three-year periods by age and avoidable cause of death groups. Avoidable mortality decreased annually by 4.6% between 2000 and 2017. There were strong age and cohort effects and a weak period effect on avoidable mortality. In the overall decreasing trend, avoidable mortality declined less in cohorts born after the 1950-1953 Korean War and economic recession in the 1970s, with further reductions in cohorts born after the 1987 democratic reform and 1997-1998 economic crisis. Avoidable mortality was reduced after implementation of major health policies, but the decrease stagnated during the 2008-2009 financial crisis. Avoidable mortality reduction resulted in LE gains of 3.1 years, which accounted for 80% of total LE gains. Contribution to LE gains by causes of death was the largest for cerebrovascular disease. Major social changes and health policies influenced the avoidable mortality trend through cohort and period effects. Health care and public health policies implemented since the 2000s might have contributed substantially to gains in LE.

The Life Expectancy Gap between Registered Disabled and Non-Disabled People in Korea from 2004 to 2017

This study aimed to estimate and compare life expectancy at birth among people with and without officially registered disabilities in Korea between 2004 and 2017. We used the National Health Information Database in Korea to obtain aggregate data on the numbers of population and deaths according to calendar year (2004 to 2017), sex, age groups, and officially registered disability status. A total of 697,503,634 subjects and 3,536,778 deaths, including 33,221,916 disabled subjects (829,464 associated deaths), were used to construct life tables. Between 2004 and 2017, life expectancy for people with disabilities increased by 9.1 years in men and 8.3 years in women, while life expectancy for the non-disabled increased by 5.5 years in men and 4.6 years in women. The average life expectancy difference between non-disabled and disabled people was 18.2 years during the study period, decreasing from 20.4 years in 2004 to 16.4 years in 2017. In 2017, the life expectancy of people with the most severe grade of disabilities was 49.7 years, while the life expectancy of people with the least severe grade of disabilities was 77.7 years. The government should implement more effective policies to protect the health of people with officially registered disabilities.

Trends in inequality in life expectancy at birth between 2004 and 2017 and projections for 2030 in Korea: multiyear cross-sectional differences by income from national health insurance data

OBJECTIVES

The current status, time trends and future projections of a national health equity target are crucial elements of national health equity surveillance. This study examined time trends in inequality by income in life expectancy (LE) at birth between 2004 and 2017 and made future projections for the year 2030 in Korea.

DESIGN

Using individually linked mortality data, time trends in inequality by income in LE at birth were examined. The LE projection was made with the Lee-Carter model.

SETTING

Total Korean population and death data derived from the National Health Information Database of the National Health Insurance Service.

PARTICIPANTS

A total of 685 773 157 subjects and 3 486 893 deaths between 2004 and 2017 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Annual LE and the magnitude of inequality by income in LE between 2004 and 2030.

RESULTS

Inequality by income in LE among the total Korean population increased during the past 14 years, and this inequality is projected to become even greater in the future. In 2030, the magnitude of inequality by income in LE is projected to increase by 0.25 years in comparison to the magnitude in 2017. The increase in LE inequality was projected to be more prominent among women, with a projected 1.08 year increase in LE inequality between 2017 and 2030.

CONCLUSION

Aggressive policies should be developed to close the increasing LE gap in Korea. LE inequalities by income should be considered as a measurable target for health equity in the process of establishing the National Health Plan 2030 in Korea.

Quantifying the impact of reducing socioeconomic inequalities in modifiable risk factors on mortality and mortality inequalities in South Korea

OBJECTIVES

We quantified the impact of reducing socioeconomic inequalities in risk factors on mortality and mortality inequalities in South Korea.

METHODS

The mortality risk function from the 12-year mortality follow-up data of the National Health Insurance Service-National Health Screening Cohort, the prevalence of major risk factors from the Korea National Health and Nutrition Examination Survey 2013-2015, and the Health Plan 2020 (HP2020) goals for major risk factors were used to estimate the magnitude of reduction in mortality inequalities by changing the magnitude of income-based inequalities in risk factors in various scenarios under gender-specific models among participants aged 40-79 years.

RESULTS

The greatest reduction in absolute and relative inequalities in mortality would occur if the low-income group achieved the HP2020 goals earlier than the high-income group. A 10-20% reduction in all-cause mortality inequalities was expected if absolute gaps between income groups in risk factors were halved.

CONCLUSIONS

With the practical goal halving the socioeconomic gaps in modifiable risk factors, reducing inequalities in all-cause mortality by 10-20% would be possible. Further reduction in mortality inequalities would need more aggressive policies on social determinants of health.

A stakeholder analysis of community-led collaboration to reduce health inequity in a deprived neighbourhood in South Korea

Intersectoral collaboration amongst health and other sectors, as well as between government and non-governmental organisations, has been highlighted as a way to improve health equity. We used a mixed-methods approach to assess collaborative relationships between multiple government sectors and civil society and to suggest possible health promotion interventions and policy alternatives for the urban poor in deprived neighborhoods. A total of 18 participants involved in health promotion interventions and policy processes related to the inner-city area of Seoul were recruited using purposive sampling methods. Participants included stakeholders working for or engaging in governments (3), public health care institutions (5), social service providers (3), community-based organisations (CBOs) (4) and faith-based organisations (3). We conducted semi-structured, one-on-one interviews and then collected survey data. Quantitative data were analysed using social network analysis, and qualitative data were analysed through iterative and consensus processes. The social network analysis indicated that a CBO plays the most substantial role in sharing and controlling informational resources to promote health. A stakeholder analysis showed that the CBO neutrally and negatively viewed the possibility of collaboration with other stakeholders. Three themes related to challenges to intersectoral collaboration emerged: (1) lack of trust and communication, (2) need of a coalition with a committed leading actor for future collaboration and (3) organisational and political silos within and across public sectors. Increased understanding of the current status of and challenges to collaboration can inform the planning and implementation of complex intervening strategies and policies tailored to vulnerable people in deprived neighborhoods. Community-led collaborative actions empower people in marginalised communities to envision a healthier community.