Educational inequality in female cancer mortality in Korea

Cancer Incidence by Occupation in Korea: Longitudinal Analysis of a Nationwide Cohort

Background

We performed this study to investigate the inequalities in site-specific cancer incidences among workers across different occupations in Korea.

Methods

Subjects included members of the national employment insurance. Incident cancers among 8,744,603 workers were followed from 1995 to 2007. Occupational groups were classified according to the Korean Standard Occupational Classification. Age-standardized incidence rate ratios were calculated.

Results

We found that men in service/sales and blue-collar occupations had elevated rates of esophageal, liver, laryngeal, and lung cancer. Among women, service/sales workers had elevated incidences of cervical cancer. Male prostate cancer, female breast, corpus uteri, and ovarian cancers, as well as male and female colorectal, kidney, and thyroid cancer showed lower incidences among workers in lower socioeconomic occupations.

Conclusions

Substantial differences in cancer incidences were found depending on occupation reflecting socioeconomic position, in the Korean working population. Cancer prevention policy should focus on addressing these socioeconomic inequalities.

Temporal trends in educational inequalities in non-communicable diseases in Korea, 2007-2015

Background

Socioeconomic inequalities in non-communicable diseases are known to exist; however there is a paucity of research describing the secular trends in these inequalities. To this end, the current study aims to explore the recent time trends in social patterning of selected non-communicable diseases among Korean adults between 2007 and 2015.

Methods

Using data from the Korea National Health and Nutrition Examination Survey (KNHANES), temporal trends in socioeconomic inequalities in diabetes, arthritis, asthma and depressive symptoms were assessed across three time points. Respondents were adults aged 20 years or over (N = 47,091, 20,180 men and 26,911 women). Socioeconomic circumstance was assessed based on highest level of educational attainment. We estimated prevalence ratios with 95% confidence intervals using Poisson regression with robust variance estimation (adjusted for age, smoking status, alcohol consumption, obesity, and physical activity) separately for men and women. The magnitude of the inequalities was computed using the relative index of inequality (RII).

Results

In men, diabetes was not associated with educational attainment, while there was evidence of a negative association in women across surveys. Similar inverse associations were found with arthritis and depressive symptoms, but these associations were less clear for asthma. RII showed a non-significant increasing trend in educational disparities in depressive symptoms. Meanwhile, relative inequalities in diabetes, arthritis and asthma have narrowed. These trends were, in general, more pronounced in women.

Conclusions

The findings of this study indicate higher burden of selected NCDs among the lower educational groups, particularly among women. In addition, our results indicated some improvements in inequalities in diabetes, arthritis and asthma in recent years. These findings have important implications for understanding the causes of social patterning of NCDs and for the targeting of effective interventions.

Increased breast cancer mortality only in the lower education group: age-period-cohort effect in breast cancer mortality by educational level in South Korea, 1983-2012

BACKGROUND

A steadily increasing pattern of breast cancer mortality has been reported in South Korea since the late 1980s. This paper explored the trends of educational inequalities of female breast cancer mortality between 1983 and 2012 in Korea, and conducted age-period-cohort (APC) analysis by educational level.

METHODS

Age-standardized mortality rates of breast cancer per 100,000 person-years were calculated. Relative index of inequality (RII) for breast cancer mortality was used as an inequality measure. APC analyses were conducted using the Web tool for APC analysis provided by the Division of Cancer Epidemiology and Genetics at the U.S. National Cancer Institute.

RESULTS

An increasing trend in breast cancer mortality among Korean women between 1983 and 2012 was due to the increased mortality of the lower education groups (i.e., no formal education or primary education and secondary education groups), not the highest education group. The breast cancer mortality was higher in women with a tertiary education than in women with no education or a primary education during 1983-1992, and the reverse was true in 1993-2012. Consequently, RII was changed from positive to negative associations in the early 2000s. The lower education groups had the increased breast cancer mortality and significant cohort and period effects between 1983 and 2012, whereas the highest group did not.

CONCLUSIONS

APC analysis by socioeconomic position used in this study could provide an important clue for the causes on breast cancer mortality. The long-term monitoring of socioeconomic patterning in breast cancer risk factors is urgently needed.

Socioeconomic inequalities in health in the context of multimorbidity: A Korean panel study

Socioeconomic inequalities in health are commonly known to decrease at late age. Yet, it remains unclear whether socioeconomic inequalities in health at late age appear in relation to multimorbidity, particularly in Korea where social support remains unsatisfactory for older people. Using three waves of Korea Health Panel, data of 19,942 observations with repeated measure were constructed to ensure a temporal sequence between three socioeconomic measures (i.e., poverty, employment status, and education) and multimorbidity with a t to t+1 year transition. A multilevel multinomial model was applied to quantify the socioeconomic impact across different age, diseases and disease groups, both separately and in combination. There were associations between socioeconomic position (SEP) and multimorbidity, and increasing trends of socioeconomic inequalities not only with greater number of morbidity but also with age. The latter result was only observed with employment status through mid-to-early old age; i.e., between the 40s (odds ratio (OR) = 2.45, 95% confidence interval (CI):1.08–5.57) and 70s (OR = 3.48, 95%CI: 1.24–9.74). The patterns of socioeconomic inequalities in multimorbidity varied for particular pairs of diseases and were stronger in the disease pairs co-occurring with mental and cardiovascular diseases but weaker in the disease pairs co-occurring with cancer. Accumulation of adversity tended to intensify with increase in number of diseases and older age, though this finding was not consistently supported. The labour market should be encouraged to actively participate in actions to promote healthy aging needs to be complemented by the provision of more generous and universal income support to the elderly in Korea.

Educational Inequality in Obesity-Related Mortality in Korea

The prevalence of obesity has been increasing worldwide, which raises concerns about the disease burden associated with obesity. Socioeconomic status (SES) has been suggested to be associated with obesity and obesity related diseases. This study aimed to evaluate the time trend in socioeconomic inequality in obesity-related mortality over the last decade in Korean population. We evaluated the influence of education level, as an indicator of SES, on obesity-related mortality using death data from the Cause of Death Statistics and the Korean Population and Housing Census databases. The rate ratio of the mortality of people at the lowest education level as compared with those at the highest education level (relative index of inequality [RII]) was estimated using Poisson regression analysis. Between 2001 and 2011, RII (95% confidence interval) for overall obesity-related disease mortality increased from 2.10 (2.02-2.19) to 6.50 (6.19-6.82) in men, and from 1.94 (1.79-2.10) to 3.25 (3.05-3.45) in women, respectively. Cause-specifically, the same trend in RII was found for cardiovascular mortality and mortality from diabetes mellitus, whereas the RII of mortality from obesity-related cancers in men did not show the similar trend. Subgroup analysis stratified by age revealed that the RII of obesity-related mortality was much higher in younger people than in older people. In conclusion, there has been persistent socioeconomic inequality in obesity-related mortality in Korea, which was more evident in younger people than in older people and has been deepened over the last decade especially for cardiovascular disease and diabetes.

Association between Socioeconomic Status and Cancer Screening in Koreans over 40 Years in Age Based on the 2010-2012 Korean National Health and Nutrition Examination Survey

BACKGROUND

We investigated the association between socioeconomic status (SES) and cancer screening in a Korean population aged 40 years or older.

METHODS

This cross-sectional study included 12,303 participants (5,284 men and 7,019 women) who participated in the 2010-2012 Korean National Health and Nutrition Examination Survey. Self-reported questionnaires were used to assess participant's SES (household income, occupational, and educational status) and cancer screening behavior.

RESULTS

Compared to the lowest household income group, the odds ratios (ORs) (95% confidence intervals [CIs]) for overall cancer screening of the highest income group were 2.113 (1.606-2.781) in men and 1.476 (1.157-1.883) in women; those for private cancer screening of the highest income group were 2.446 (1.800-3.324) in men and 2.630 (2.050-3.373) in women, while those for National Cancer Screening Programs (NCSP) in the highest income group were 1.076 (0.805-1.439) in men and 0.492 (0.388-0.623) in women. Compared to manual workers, ORs (95% CIs) for private cancer screening of office workers were 1.300 (1.018-1.660) in men and 0.822 (0.616-1.098) in women. In comparison to the least educated men, OR (95% CI) for private cancer screening of the most educated men was statistically significant (1.530 [1.117-2.095]).

CONCLUSION

Higher economic status was associated with higher rates of overall and private cancer screening in both sexes and a lower rate of NCSP in women. Male office workers and more educated individuals underwent private cancer screening at a higher rate than manual workers and less educated individuals, respectively.

Mortality rates by occupation in Korea: a nationwide, 13-year follow-up study

OBJECTIVE

The present study sought to identify inequalities in cause-specific mortality across different occupational groups in Korea.

METHODS

The cohort included Korean workers enrolled in the national employment insurance programme between 1995 and 2000. Mortality was determined by matching death between 1995 and 2009 according to a nationwide registry of the Korea National Statistical Office. The cohort was divided into nine occupational groups according to the Korean Standard Occupational Classification (KSOC). Age-standardised mortality rates of each subcohort were calculated.

RESULTS

The highest age-standardised mortality rate was identified in KSOC 6 (agricultural, forestry and fishery workers; male (M): 563.0 per 100 000, female (F): 206.0 per 100 000), followed by KSOC 9 (elementary occupations; M: 499.0, F: 163.4) and KSOC 8 (plant, machine operators and assemblers; M: 380.3, F: 157.8). The lowest rate occurred in KSOC 2 (professionals and related workers; M: 209.1, F: 93.3). Differences in mortality rates between KSOC 2 and KSOC 9 (M: 289.9, F: 70.1) and the rate ratio of KSCO9 to KSCO2 (M: 2.39, F: 1.75) were higher in men. The most prominent mortality rate difference was observed in external causes of death (M: 96.9, F: 21.6) and liver disease in men (38.3 per 100 000). Mental disease showed the highest rate ratio (M: 6.31, F: 13.00).

CONCLUSIONS

Substantial differences in mortality rates by occupation were identified. Main causes of death were injury, suicide and male liver disease. Development of policies to support occupations linked with a lower socioeconomic position should be prioritised.