Cancer is overtaking cardiovascular disease as the main driver of socioeconomic inequalities in mortality: New Zealand (1981-99)

Contribution of causes of death to changing inequalities in life expectancy by income in Finland, 1997-2020

BACKGROUND

Socioeconomic inequalities in mortality originate from different causes of death. Alcohol-related and smoking-related deaths are major drivers of mortality inequalities across Europe. In Finland, the turn from widening to narrowing mortality disparities by income in the early 2010s was largely attributable to these causes of death. However, little is known about recent inequalities in life expectancy (LE) and lifespan variation.

METHODS

We used individual-level total population register-based data with annual information on disposable household income and cause-specific mortality for ages 30-95+, and assessed the contribution of smoking on mortality using the Preston-Glei-Wilmoth method. We calculated trends in LE at age 30 and SD in lifespan by income quintile in 1997-2020 and conducted age and cause-of-death decompositions of changes in LE.

RESULTS

Disparity in LE and lifespan variation by income increased in 2015-2020, largely attributable to the stagnation of both measures in the lowest income quintile. The LE gap between the extreme quintiles in 2018-2020 was 11.2 (men) and 5.9 (women) years, of which roughly 40% was attributable to alcohol and smoking. However, the recent widening of the gap and the stagnation in LE in the lowest quintile over time were not driven by any specific cause-of-death group.

CONCLUSIONS

After a decade of narrowing inequalities in LE and lifespan variation in Finland, the gaps between income groups are growing again. Increasing LE disparity and stagnating mortality on the lowest income levels are no longer attributable to smoking and alcohol-related deaths but are more comprehensive, originating from most cause-of-death groups.

Spatio-Temporal Variation of Lung Cancer in Crete, 1992-2013. Economic or Health Crisis?

(1) Background: This is the first population-based study in Greece, with the aim to measure the changing trends of lung cancer (LC) and the associated risk factors before and after the economic crisis. Among the main objectives were the identification of LC hot spots and high-risk areas; (2) Methods: The study was conducted in Crete, the biggest island in Greece. Data (5057 LC cases) were collected from the Cancer Registry of Crete (CRC). The age-standardized incidence and mortality rates (ASIR, ASMR/100,000/year) were estimated, while additional indexes were used, including the adjusted Charlson's comorbidity index (CCI%), the deprivation index (HPI-2), and the exposure to outdoor air pollution (OAP). The analysis was performed for two time periods (Period A: 1992-2008; Period B: 2009-2013); (3) Results: ASIR presented a significant increase during the economic crisis, while an even higher increase was observed in ASMR (Period A: ASMR = 30.5/100,000/year; Period B: ASMR = 43.8/100,000/year; p < 0.001). After 2009, a significant increase in the observed LC hot spots was identified in several sub-regions in Crete (p = 0.04). The risk of LC mortality increased even more for smokers (RR = 5.7; 95%CI = 5.2-6.3) and those living in highly deprived geographical regions (RR = 5.4; 95%CI = 5.1-5.8) during the austerity period. The multiple effect of LC predictors resulted in adjusted RRs ranging from 0.7 to 5.7 within the island (p < 0.05); (4) Conclusions: The increased LC burden after the onset of the economic crisis, along with a changing pattern of LC predictors stressed the urgent need of geographically oriented interventions and cancer control programs focusing on the most deprived or vulnerable population groups.

Long-term trends in smoking prevalence and its socioeconomic inequalities in Korea, 1992-2016

BACKGROUND

The aim of this study was to investigate long-term trends in smoking prevalence and its socioeconomic inequalities in Korea.

METHODS

Data were collected from 10 rounds of the Social Survey of Statistics Korea between 1992 and 2016. A total of 524,866 men and women aged 19 or over were analyzed. Age-adjusted smoking prevalence was calculated according to three major socioeconomic position indicators: education, occupational class, and income. The prevalence difference, prevalence ratio, slope index of inequality (SII), and relative index of inequality (RII) were calculated to examine the magnitude of inequality in smoking.

RESULTS

Smoking prevalence among men decreased from 71.7% in 1992 to 39.7% in 2016, while smoking prevalence among women decreased from 6.5% in 1992 to 3.3% in 2016. Socioeconomic inequalities in smoking prevalence according to the three socioeconomic position indicators were found in both men and women throughout the study period. In general, absolute and relative socioeconomic inequalities in smoking, measured by prevalence difference and prevalence ratio for education and occupational class, widened during the study period among Korean men and women. In men, the SII for income increased from 7.6% in 1999 to 10.8% in 2016 and the RII for income also increased from 1.11 in 1999 to 1.31 in 2016. In women, the SII for income increased from 0.1% in 1999 to 2.4% in 2016 and the RII for income increased from 1.39 in 1999 to 2.25 in 2016.

CONCLUSION

Pro-rich socioeconomic inequalities in smoking prevalence were found in men and women. Socioeconomic inequalities in smoking have increased in parallel with the implementation of tobacco control policies. Tobacco control policies should be developed to decrease socioeconomic inequalities in cigarette use in Korea.

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.

Trends in Inequality in Cigarette Smoking Prevalence by Income According to Recent Anti-smoking Policies in Korea: Use of Three National Surveys

Objectives

This study examined trends in inequality in cigarette smoking prevalence by income according to recent anti-smoking policies in Korea.

Methods

The data used in this study were drawn from three nationally representative surveys, the Korea National Health and Nutrition Examination Survey, the Korea Community Health Survey, and the Social Survey of Statistics Korea. We calculated the age-standardized smoking prevalence, the slope index of inequality, and the relative index of inequality by income level as a socioeconomic position indicator.

Results

Smoking prevalence among men decreased during the study period, but the downward trend became especially pronounced in 2015, when the tobacco price was substantially increased. Inequalities in cigarette smoking by income were evident in both genders over the study period in all three national surveys examined. Absolute inequality tended to decrease between 2014 and 2015 among men. Absolute and relative inequality by income decreased between 2008 and 2016 in women aged 30-59, except between 2014 and 2015.

Conclusions

The recent anti-smoking policies in Korea resulted in a downward trend in smoking prevalence among men, but not in relative inequality, throughout the study period. Absolute inequality decreased over the study period among men aged 30-59. A more aggressive tax policy is warranted to further reduce socioeconomic inequalities in smoking in young adults in Korea.

Changes in mortality inequalities across occupations in Japan: a national register based study of absolute and relative measures, 1980-2010

OBJECTIVE

Changes in mortality inequalities across socioeconomic groups have been a substantial public health concern worldwide. We investigated changes in absolute/relative mortality inequalities across occupations, and the contribution of different diseases to inequalities in tandem with the restructuring of the Japanese economy.

METHODS

Using complete Japanese national death registries from 5 year intervals (1980-2010), all cause and cause specific age standardised mortality rates (ASMR per 100 000 people standardised using the Japanese standard population in 1985, aged 30-59 years) across 12 occupations were computed. Absolute and relative inequalities were measured in ASMR differences (RDs) and ASMR ratios (RRs) among occupations in comparison with manufacturing workers (reference). We also estimated the changing contribution of different diseases by calculating the differences in ASMR change between 1995 and 2010 for occupations and reference.

RESULTS

All cause ASMRs tended to decrease in both sexes over the three decades except for male managers (increased by 71% points, 1995-2010). RDs across occupations were reduced for both sexes (civil servants 233.5 to -1.9 for men; sales workers 63.3 to 4.5 for women) but RRs increased for some occupations (professional workers 1.38 to 1.70; service workers 2.35 to 3.73) for men and decreased for women from 1980 to 2010. Male relative inequalities widened among farmer, fishery and service workers, because the percentage declines were smaller in these occupations. Cerebrovascular disease and cancer were the main causes of the decrease in mortality inequalities among sexes but the incidence of suicide increased among men, thereby increasing sex related inequalities.

CONCLUSIONS

Absolute inequality trends in mortality across occupations decreased in both sexes, while relative inequality trends were heterogeneous in Japan. The main drivers of narrowing and widening mortality inequalities were cerebrovascular disease and suicide, respectively. Future public health efforts will benefit from eliminating residual inequalities in mortality by considering the contribution of the causes of death and socioeconomic status stratification.

Changing socioeconomic inequalities in cancer incidence and mortality: Cohort study with 54 million person-years follow-up 1981-2011

Cancer is increasingly responsible for the mortality gap between high and low socioeconomic position groups in high-income countries. This study investigates which cancers are contributing more to socioeconomic gaps in mortality and how this changes over time.New Zealand census data from 1981, 1986, 1991, 1996, 2001 and 2006, were linked to three to five years of subsequent mortality and cancer registrations, resulting in 54 and 42 million years of follow-up cancer incidence and mortality, respectively. Age- and ethnicity-standardised cancer mortality rates and the slope index of inequality (SII) by income were calculated.The contribution of cancer to absolute inequalities (SII) in mortality increased from 16 to 27% for men and from 12 to 31% for women from 1981-84 to 2006-11, peaking in 1991-94 for men and in 1996-99 for women and then levelling off, parallel to peaks in lung cancer inequalities. Lung cancer was the largest driver of cancer inequality trends (49% of the cancer mortality gap in 1981-84 to 33% in 2006-11 for men and 32 to 33% for women) followed by colorectal cancer in men (2 to 11%) and breast cancer in women (declining from 44 to 13%). Women in the lowest income quintile experienced no decline in cancer mortality.The contribution of cancer to income inequalities in all-cause mortality has expanded in this high-income country. Action to address socioeconomic inequalities should prioritise equitable tobacco control, obesity control and improved access to cancer screening, early diagnosis and high quality treatment for those with the lowest incomes.

Trends in educational inequalities in premature mortality in Belgium between the 1990s and the 2000s: the contribution of specific causes of deaths

BACKGROUND

Reducing socioeconomic inequalities in mortality, a key public health objective may be supported by a careful monitoring and assessment of the contributions of specific causes of death to the global inequality.

METHODS

The 1991 and 2001 Belgian censuses were linked with cause-of-death data, each yielding a study population of over 5 million individuals aged 25-64, followed up for 5 years. Age-standardised mortality rates (ASMR) were computed by educational level (EL) and cause. Inequalities were measured through rate differences (RDs), rate ratios (RRs) and population attributable fractions (PAFs). We analysed changes in educational inequalities between the 1990s and the 2000s, and decomposed the PAF into the main causes of death.

RESULTS

All-cause and avoidable ASMR decreased in all ELs and both sexes. Lung cancer, ischaemic heart disease (IHD), chronic obstructive pulmonary disease (COPD) and suicide in men, and IHD, stroke, lung cancer and COPD in women had the highest impact on population mortality. RDs decreased in men but increased in women. RRs and PAFs increased in both sexes, albeit more in women. In men, the impact of lung cancer and COPD inequalities on population mortality decreased while that of suicide and IHD increased. In women, the impact of all causes except IHD increased.

CONCLUSION

Absolute inequalities decreased in men while increasing in women; relative inequalities increased in both sexes. The PAFs decomposition revealed that targeting mortality inequalities from lung cancer, IHD, COPD in both sexes, suicide in men and stroke in women would have the largest impact at population level.

Ethnic inequalities in cancer incidence and mortality: census-linked cohort studies with 87 million years of person-time follow-up

BACKGROUND

Cancer makes up a large and increasing proportion of excess mortality for indigenous, marginalised and socioeconomically deprived populations, and much of this inequality is preventable. This study aimed to determine which cancers give rise to changing ethnic inequalities over time.

METHODS

New Zealand census data from 1981, 1986, 1991, 1996, 2001, and 2006, were all probabilistically linked to three to five subsequent years of mortality (68 million person-years) and cancer registrations (87 million person years) and weighted for linkage bias. Age-standardised rate differences (SRDs) for Māori (indigenous) and Pacific peoples, each compared to European/Other, were decomposed by cancer type.

RESULTS

The absolute size and percentage of the cancer contribution to excess mortality increased from 1981-86 to 2006-11 in Māori males (SRD 72.5 to 102.0 per 100,000) and females (SRD 72.2 to 109.4), and Pacific females (SRD -9.8 to 42.2) each compared to European/Other. Specifically, excess mortality (SRDs) increased for breast cancer in Māori females (linear trend p < 0.01) and prostate (p < 0.01) and colorectal cancers (p < 0.01) in Māori males. The incidence gap (SRDs) increased for breast (Māori and Pacific females p < 0.01), endometrial (Pacific females p < 0.01) and liver cancers (Māori males p = 0.04), and for cervical cancer it decreased (Māori females p = 0.03). The colorectal cancer incidence gap which formerly favoured Māori, decreased for Māori males and females (p < 0.01). The greatest contributors to absolute inequalities (SRDs) in mortality in 2006-11 were lung cancer (Māori males 50 %, Māori females 44 %, Pacific males 81 %), breast cancer (Māori females 18 %, Pacific females 23 %) and stomach cancers (Māori males 9 %, Pacific males 16 %, Pacific females 20 %). The top contributors to the ethnic gap in cancer incidence were lung, breast, stomach, endometrial and liver cancer.

CONCLUSIONS

A transition is occurring in what diseases contribute to inequalities. The increasing excess incidence and mortality rates in several obesity- and health care access-related cancers provide a sentinel warning of the emerging drivers of ethnic inequalities. Action to further address inequalities in cancer burden needs to be multi-pronged with attention to enhanced control of tobacco, obesity, and carcinogenic infectious agents, and focus on addressing access to effective screening and quality health care.

Relative index of inequality and slope index of inequality: a structured regression framework for estimation

BACKGROUND

The relative index of inequality and the slope index of inequality are the two major indices used in epidemiologic studies for the measurement of socioeconomic inequalities in health. Yet the current definitions of these indices are not adapted to their main purpose, which is to provide summary measures of the linear association between socioeconomic status and health in a way that enables valid between-population comparisons. The lack of appropriate definitions has dissuaded the application of suitable regression methods for estimating the slope index of inequality.

METHODS

We suggest formally defining the relative and slope indices of inequality as so-called least false parameters, or more precisely, as the parameters that provide the best approximation of the relation between socioeconomic status and the health outcome by log-linear and linear models, respectively. From this standpoint, we establish a structured regression framework for inference on these indices. Guidelines for implementation of the methods, including R and SAS codes, are provided.

RESULTS

The new definitions yield appropriate summary measures of the linear association across the entire socioeconomic scale, suitable for comparative studies in epidemiology. Our regression-based approach for estimation of the slope index of inequality contributes to an advancement of the current methodology, which mainly consists of a heuristic formula relying on restrictive assumptions. A study of the educational inequalities in all-cause and cause-specific mortality in France is used for illustration.

CONCLUSION

The proposed definitions and methods should guide the use and estimation of these indices in future studies.

Diverging trends in educational inequalities in cancer mortality between men and women in the 2000s in France

BACKGROUND

Socioeconomic inequalities in cancer mortality have been observed in different European countries and the US until the end of the 1990s, with changes over time in the magnitude of these inequalities and contrasted situations between countries. The aim of this study is to estimate relative and absolute educational differences in cancer mortality in France between 1999 and 2007, and to compare these inequalities with those reported during the 1990s.

METHODS

Data from a representative sample including 1% of the French population were analysed. Educational differences among people aged 30-74 were quantified with hazard ratios and relative indices of inequality (RII) computed using Cox regression models as well as mortality rate difference and population attributable fraction.

RESULTS

In the period 1999-2007, large relative inequalities were found among men for total cancer and smoking and/or alcohol related cancers mortality (lung, head and neck, oesophagus). Among women, educational differences were reported for total cancer, head and neck and uterus cancer mortality. No association was found between education and breast cancer mortality. Slight educational differences in colorectal cancer mortality were observed in men and women. For most frequent cancers, no change was observed in the magnitude of relative inequalities in mortality between the 1990s and the 2000s, although the RII for lung cancer increased both in men and women. Among women, a large increase in absolute inequalities in mortality was observed for all cancers combined, lung, head and neck and colorectal cancer. In contrast, among men, absolute inequalities in mortality decreased for all smoking and/or alcohol related cancers.

CONCLUSION

Although social inequalities in cancer mortality are still high among men, an encouraging trend is observed. Among women though, the situation regarding social inequalities is less favourable, mainly due to a health improvement limited to higher educated women. These inequalities may be expected to further increase in future years.

Socio-economic inequalities in mortality persist into old age in New Zealand: study of all 65 years plus, 2001–04

A number of studies have explored the relationship between socio-economic status and mortality, although these have mostly been based on the working-age population, despite the fact that the burden of mortality is highest in older people. Using Poisson regression on linked New Zealand census and mortality data (2001–04, 1.3 million person years) with a comprehensive set of socio-economic indicators (education, income, car access, housing tenure, neighourhood deprivation), we examined the association of socio-economic characteristics and older adult mortality (65+ years) in New Zealand. We found that socio-economic mortality gradients persist into old age. Substantial relative risks of mortality were observed for all socio-economic factors, except housing tenure. Most relative risk associations decreased in strength with ageing [e.g. most deprived compared to least deprived rate ratio for males reducing from 1.40 (95% confidence interval (CI) 1.28–1.53) for 65–74-year-olds to 1.13 (CI 1.00–1.28) for 85 + -year-olds], except for income and education among women where the rate ratios changed little with increasing age. This suggests individual-level measures of socio-economic status are more closely related to mortality in older women than older men. Comparing across genders, the only statistically significantly different association between men and women was for a weaker association for women for car access.

Changes in contribution of causes of death to socioeconomic mortality inequalities in Korean adults

Objectives

This study aimed to analyze long-term trends in the contribution of each cause of death to socioeconomic inequalities in all-cause mortality among Korean adults.

Methods

Data were collected from death certificates between 1990 and 2004 and from censuses in 1990, 1995, and 2000. Age-standardized death rates by gender were produced according to education as the socioeconomic position indicator, and the slope index of inequality was calculated to evaluate the contribution of each cause of death to socioeconomic inequalities in all-cause mortality.

Results

Among adults aged 25-44, accidental injuries with transport accidents, suicide, liver disease and cerebrovascular disease made relatively large contributions to socioeconomic inequalities in all-cause mortality, while, among adults aged 45-64, liver disease, cerebrovascular disease, transport accidents, liver cancer, and lung cancer did so. Ischemic heart disease, a very important contributor to socioeconomic mortality inequality in North America and Western Europe, showed a very low contribution (less than 3%) in both genders of Koreans.

Conclusions

Considering the contributions of different causes of death to absolute mortality inequalities, establishing effective strategies to reduce socioeconomic inequalities in mortality is warranted.

Shrinking, widening, reversing, and stagnating trends in US socioeconomic inequities in cancer mortality for the total, black, and white populations: 1960-2006

OBJECTIVES OF STUDY

To test recent claims that cancer inequities are bound to increase as population health improves.

METHODS

We analyzed 1960-2006 age-standardized US county cancer mortality data, total and site-specific (lung, prostate, colorectal, breast, cervix, stomach), stratified by county income quintile for the US total, black, and white populations.

RESULTS

Between 1960 and 2006, US socioeconomic inequities in cancer mortality variously shrunk, widened, reversed, and stagnated, depending on time period and cancer site. For all cancers combined and most, but not all, sites, absolute, but not relative, socioeconomic gaps were greater for the black compared to white population. Compared to the yearly age-specific mortality rates among whites in the most affluent counties, the percent of excess cancer deaths among whites in the lower four county income quintiles first rose above 0 in 1990 and in 2006 equaled 5.4% (95% CI 4.8, 6.0); among blacks, it rose from 6.0% (95% CI 4.5, 7.4) in 1960 to 24.7% (95% CI 23.9, 25.5) in 1990 and remained at this level through 2006.

CONCLUSIONS

The hypothesis that cancer mortality inequities are bound to increase is refuted by long-term data on total and site-specific cancer mortality stratified by socioeconomic position and race/ethnicity.

Inequalities in mortality during and after restructuring of the New Zealand economy: repeated cohort studies

OBJECTIVES

To determine whether disparities between income and mortality changed during a period of major structural and macroeconomic reform and to estimate the changing contribution of different diseases to these disparities.

DESIGN

Repeated cohort studies.

DATA SOURCES

1981, 1986, 1991, 1996, and 2001 censuses linked to mortality data. Population Total New Zealand population, ages 1-74 years.

METHODS

Mortality rates standardised for age and ethnicity were calculated for each census cohort by level of household income. Standardised rate differences and rate ratios, and slope and relative indices of inequality (SII and RII), were calculated to measure disparities on both absolute and relative scales.

RESULTS

All cause mortality rates declined over the 25 year study period in all groups stratified by sex, age, and income, except for 25-44 year olds of both sexes on low incomes among whom there was little change. In all age groups pooled, relative inequalities increased from 1981-4 to 1996-9 (RIIs increased from 1.85 (95% confidence interval 1.67 to 2.04) to 2.54 (2.29 to 2.82) for males and from 1.54 (1.35 to 1.76) to 2.12 (1.88 to 2.39) for females), then stabilised in 2001-4 (RIIs of 2.60 (2.34 to 2.89) and 2.18 (1.93 to 2.45), respectively). Absolute inequalities were stable over time, with a possible fall from 1996-9 to 2001-4. Cardiovascular disease was the major contributor to the observed disparities between income and mortality but decreased in importance from 45% in 1981-4 to 33% in 2001-4 for males and from 50% to 29% for females. The corresponding contribution of cancer increased from 16% to 22% for males and from 12% to 25% for females.

CONCLUSIONS

During and after restructuring of the economy disparities in mortality between income groups in New Zealand increased in relative terms (but not in absolute terms), but it is difficult to confidently draw a causal link with structural reforms. The contribution of different causes of death to this inequality changed over time, indicating a need to re-prioritise health policy accordingly.

Effects of passive smoking on heart rate variability, heart rate and blood pressure: an observational study

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been shown to increase the risk for cardiovascular diseases and death, and autonomic dysfunction (specifically, reduced heart rate variability (HRV)) is a predictor of increased cardiac risk. This study tests the hypothesis that ETS exposure reduces HRV in the general population and discusses possible pathways.

METHODS

This cross-sectional study was conducted between 2001 and 2003 and is part of the SAPALDIA (Swiss Cohort Study on Air Pollution and Lung Diseases in Adults) study. The analysis included 1218 randomly selected non-smokers aged 50 and above who participated in 24-h electrocardiogram recordings. Other examinations included an interview, investigating health status (especially respiratory and cardiovascular health and health relevant behaviours and exposure to ETS) and measurements of blood pressure, body height and weight.

RESULTS

Subjects exposed to ETS at home or at work for more than 2 h/day had a difference of -15% in total power (95%CI: -26 to -3%), low frequency power (-28 to -1%), low/high frequency ratio (-26 to -3%) and -18% (-29 to -4%) in ultralow frequency power of HRV compared with subjects not exposed to ETS at home or work. We also found a 2.7% (-0.01 to 5.34%) higher heart rate during the recording in exposed subjects.

CONCLUSIONS

Exposure to ETS at home and work is associated with lower HRV and with higher heart rate in an ageing population. Our findings suggest that exposure to ETS increases cardiac risk through disturbances in the autonomic nervous system.