Social and geographic inequalities in premature adult mortality in Japan: a multilevel observational study from 1970 to 2005

Changes in cause-specific mortality trends across occupations in working-age Japanese women from 1980 to 2015: a cross-sectional analysis

Background

Reducing health inequalities is an important public health challenge. Many studies have examined the widening health gap by occupational class among men, but few among women. We therefore estimated variation in absolute and relative mortality by occupational category across four leading causes of mortality—cancer, ischaemic heart disease, cerebrovascular disease, and suicide—to explore how occupational class is associated with health among working women aged 25–64 in Japan.

Methods

We conducted a repeated cross-sectional study using Poisson regression analysis on each five-yearly mortality data from 1980 to 2015, obtained from the National Vital Statistics and the Japanese Population Census.

Results

There was a decreasing trend in mortality from all cancers, ischaemic heart disease, cerebrovascular disease, and suicide among women in all occupational groups from 1980 to 2015. Agriculture workers had higher risk of mortality than professional workers for all four causes of death. The absolute difference in mortality rates for all cancers and cerebrovascular disease was higher in 2000–2015 than 1980–1995. The mortality trend among clerks and sales workers decreased after 2000, except for suicide.

Conclusions

Mortality rates from all four causes are higher among agriculture workers compared to professional workers, and attention is needed to reduce this mortality gap. Continuous monitoring of ongoing mortality trends is essential to ensure better health and wellbeing in Japan.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01621-4.

Neighbourhood Social Determinants of Health and Geographical Inequalities in Premature Mortality in Taiwan: A Spatiotemporal Approach

Geographical inequalities in premature mortality and the role of neighbourhood social determinants of health (SDOH) have been less explored. This study aims to assess the geographical inequalities in premature mortality in Taiwan and how neighbourhood SDOH contribute to them and to examine the place-specific associations between neighbourhood SDOH and premature mortality. We used township-level nationwide data for the years 2015 to 2019, including age-standardized premature mortality rates and three upstream SDOH (ethnicity, education, and income). Space-time scan statistics were used to assess the geographical inequality in premature mortality. A geographical and temporal weighted regression was applied to assess spatial heterogeneity and how neighbourhood SDOH contribute to geographic variation in premature mortality. We found geographical inequality in premature mortality to be clearly clustered around mountainous rural and indigenous areas. The association between neighbourhood SDOH and premature mortality was shown to be area-specific. Ethnicity and education could explain nearly 84% variation in premature mortality. After adjusting for neighbourhood SDOH, only a handful of hotspots for premature mortality remained, mainly consisting of rural and indigenous areas in the central-south region of Taiwan. These findings provide empirical evidence for developing locally tailored public health programs for geographical priority areas.

Trends and differences in alcohol-related mortality rates by gender and by prefectures in Japan between 1995 and 2016

BACKGROUND

This study aimed to identify increases in 100 % alcohol-related death (ARD) and any differences among prefectures between 1995-2016.

METHODS

Data from the national death registry on 100 % ARDs between 1995-2016 were extracted. Age-standardized mortality rate (ASMR) of 100 % ARD by year, gender, and gender ratio were calculated. After dividing the period into 1995-2005 and 2006-2016, the ASMRs of 100 % ARDs were calculated by prefecture. Additionally, based on geographical area, municipality size, or annual alcohol sales per adult in each prefecture, prefectures were divided into groups and analysed.

RESULTS

In total, 95,455 deaths were caused by 100 % ARD from 1995-2016. Men's ASMRs of 100 % ARD markedly increased from 4.0 per 100,000 in 1995 to 5.2 between 2010 and 2013, and gradually declined to 5.0 in 2016. Women's ASMRs increased steadily from 0.3 in 1995 to 0.8 in 2016. The gender ratio of ASMRs decreased from 13.3 in 1995 to 6.3 in 2016. The ASMR of one prefecture, which had reduced alcohol tax rates, was higher for both genders. Both men's and women's ASMRs were higher in the prefectures that had higher alcohol sales (6.3 [5.0-7.7] and 0.8 [0.6-1.1], respectively) compared to the prefectures that had lower alcohol sales (4.3 [4.0-4.7] p < 0.001 and 0.6 [0.5-0.6] p = 0.045, respectively).

CONCLUSIONS

The ASMR of 100 % ARD remained high for men and increased for women, and prefecture-level higher alcohol sales and lower tax rates correlated with the higher mortality rate. Increasing prices and taxes and reducing alcohol sales may contribute to a decrease in alcohol-related mortality.

The Association between Occupational Categories and Incidence of Cardiovascular Events: A Cohort Study in Iranian Male Population

Background:

Besides the traditional cardiovascular risk factor, some novel risk factors like occupation and career can play an important role in cardiovascular disease (CVDs) incidence.

Objective:

To assess the association between occupational categories and their positions with cardiovascular events (CVEs) in an Iranian male population.

Methods:

We followed 2134 men aged 35–65 years for 14 years during the Isfahan Cohort Study (2001–2015) for CVEs including ischemic heart disease and stroke. Firstly, Occupations were classified into 10 categories of International Standard Classification of Occupation (ISCO). Each category was then classified into one of the 4 pre-specified categories, namely high/low skilled white collars and high/low skilled blue collars. White-collar workers referred to managerial and professional workers in contrast with blue collar workers, whose job requires manual labor.

Results:

The mean age of studied participants was 46.9 (SD 8.3) years. 286 CVE incidents were recorded; unstable angina had the highest rate (46%); fatal stroke, the lowest (3%). There were no significant difference was observed between white and blue collars in terms of CVE incidence, as well as their high and low skilled subgroups. Hazard ratio analysis indicated a significantly higher risk of CVEs only for low-skilled white-collar workers (crude HR 1.47, 95% CI 1.01 to 2.13); this was not significant after adjustment for confounding variables.

Conclusion:

There is no association between occupational categories and incidence of cardiovascular events among Iranian male population.

Association between Cardiovascular Mortality and Economic Development: A Spatio-Temporal Study for Prefectures in Japan

In this paper, we use a bivariate choropleth map to investigate the relationship between mortality from cardiovascular disease (CVD) and gross domestic product (GDP) per capita, by sex, in Japanese prefectures from 1996 to 2015. The overall results show a decline in age-standardized CVD mortality rates in all prefectures, for both men and women, and suggest that GDP per capita has varied over the period. We also observed that the relationship between CVD mortality rates and GDP per capita at the prefecture level does not have an overall pattern of the same or inverse association, but is instead a heterogeneous relationship. We argue that this study provides useful clues to policy makers for establishing effective measures for public health planning and the prevention of deaths from CVD. As demonstrated by this study, mapping of the CVD burden in Japan helps to clarify regional differences in life expectancy and health status across regions and identify prefectures where more targeted policy attention may be needed.

A Serial Cross-Sectional Analysis of the Prevalence, Risk Factors and Geographic Variations of Reduced Visual Acuity in Primary and Secondary Students from 2000 to 2017 in Hong Kong

Background: We would like to investigate the prevalence trend, potential risk factors and geographic features of reduced visual acuity (VA) in primary and secondary schoolchildren of Hong Kong. Methods: This was a serial cross-sectional study using historical data of schoolchildren aged 6 to 15 years from the annual health checks conducted at Student Health Service Centers across Hong Kong, for the school years of 2000/2001 to 2016/2017. Results: The prevalence of reduced VA increased from 49.23% (95% CI, 48.99-49.47) in 2000/2001 to 54.34% (95% CI, 54.10-54.58) in 2011/2012 but decreased to 51.42% (95% CI, 51.17-51.66) in 2016/2017. Girls were less susceptible than boys at age 6-7 (and in grade primary 1-2), but more susceptible at older ages. The prevalence in junior grades increased while the risk effect of grade reduced over the past 17 years. Geographic variation on the risk for reduced VA existed and spatial autocorrelation was positive. The difference in prevalence of reduced VA between Hong Kong and mainland China has decreased in recent years. Cross-border students living in mainland China were associated with a lower risk for reduced VA. Conclusions: Further study was proposed to investigate the environmental association between students living in and outside Hong Kong with the prevalence of reduced VA. Multi-level research should also be conducted to investigate the influence of compositional and contextual factors on the prevalence of reduced VA.

Occupational Differences in C-Reactive Protein Among Working-Age Adults in South Korea

OBJECTIVE

To examine the association between occupational class and high-sensitivity C-reactive protein (hsCRP) in Korean workers.

METHODS

We used a nationally representative sample of Koreans (n = 2591) aged 19 to 65 years from the 2015 Korea National Health and Nutrition Examination Survey. The concentration of hsCRP (mg/L) was assessed by a high sensitivity immunoturbidimetric assay. Current occupation was categorized as: white-collar (managers/professionals), pink-collar (clerks/service/sales), blue-collar (craft/equipment/machine-assembling, agricultural/forestry/fishery, and elementary-level labor), or unemployed. Cross-sectional linear regression models adjusted for sociodemographic/work-related/health conditions and behaviors.

RESULTS

Compared with blue-collar workers, white-collar workers showed significantly higher levels of hsCRP (β = 0.16, 95% CI: 0.02, 0.30) after adjusting for all covariates, whereby the pattern was more pronounced among professionals. However, the association was not significant for unemployed and pink-collar workers.

CONCLUSIONS

Findings suggest that Korean white-collar workers, particularly professionals, have elevated levels of inflammation.

Influence of Key Health Related Indicators on Adult Mortality: Result from UN Member Countries

BACKGROUND

Adult mortality is associated with different demographic and behavioral risk factors including approaches to health care financing. Adult mortality rate significantly reflects the effectiveness of public health-related program and intervention. The aim of this study was to find strength of association between key health's related indicators and adult mortality rate.

METHODS

This cross-sectional study used 5 sets of data combined into one from different organizations of 193 countries using record linkage theory. Eleven key health-related indicators were taken as independent variables and adult mortality of male and female were dependent variables from 2010 to 2013. Average mortality for male and female was shown by means and standard deviations, raw association by Pearson correlation and strength of association by hierarchical linear regression.

RESULTS

The average adult mortality rate (AMR) of male was 0.209±0.106 and of female, 0.146 ±0.105 in years. In raw correlation, almost all health indicators were associated with AMR of male and female. In regression analysis, Universal Health Coverage (UHC) significantly reduced (male ∼0.43, female ∼0.30) adult mortality, in contrast, population growth significantly increased (male ∼ 0.37, female ∼0.43). Alcohol consumption per year increased AMR in male by 0.41 (P<0.01) and vaccination coverage (DPT 3) significantly reduced the AMR (0.26) in female.

CONCLUSION

It is necessary to extend the UHC in remaining countries and still a need to control the population where there is high population growth. Effectively control of alcoholic drink in male and full coverage of vaccination in childhood mitigates adult mortality. The UHC is ambitious goal for SDG and special attention should be provided nationally and globally.

An analysis of factors related to disability-free life expectancy at 65 years of age across Japanese prefectures in 2010

Compared to the large volume of research focused on mortality differentials within Japan, relatively little is known about regional variations in health expectancy, particularly among older people. This article has two interrelated objectives. The first objective is to estimate prefecture-specific disability-free life expectancy (DFLE) at 65 years of age in 2010. DFLE at 65 by gender and prefecture was computed using the Sullivan method, which was applied to prefecture-specific life tables and prevalence of disability from Kokumin Seikatsu Kiso Chosa (Comprehensive Survey of Living Conditions) of 2010. The second objective is to investigate macro-level factors associated with DFLE at 65 across 47 Japanese prefectures. Our results indicate regional disparities in DFLE at older ages. Importantly, we note close relationships between a prefecture's wealth, labor, and welfare characteristics and DFLE at 65. Income per capita, the proportion of workers older than 65, and welfare expenditures are positively related to DFLE, whereas unemployment and long-term care insurance expenditures per-capita are inversely associated with DFLE for both genders. The proportion of older adults relying on public assistance is negatively related only to women's DFLE. These results suggest that narrowing socioeconomic disparities may contribute to the health of Japanese elders. Reducing regional health disparities therefore requires policy makers to take into account the broader socioeconomic conditions of each prefecture.

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.

Sociodemographic patterning of long-term diabetes mellitus control following Japan's 3.11 triple disaster: a retrospective cohort study

OBJECTIVE

To assess the sociodemographic patterning of changes in glycaemic control of patients with diabetes affected by the 2011 triple disaster in Japan (earthquake, tsunami and nuclear accident).

METHODS

A retrospective cohort study was undertaken with 404 patients with diabetes at a public hospital in Minamisoma City, Fukushima Prefecture. Glycated haemoglobin (HbA1c) levels were measured in 2010, 2011 and 2012 to capture changes in glycaemic control postdisaster. Age, sex, urban/rural residency, evacuation status and medication use were also assessed.

RESULTS

There was an overall deterioration in glycaemic control after the disaster, with the mean HbA1c rising from 6.77% in 2010 to 6.90% in 2012 (National Glycohemoglobin Standardization Program, NGSP). Rural residency was associated with a lower likelihood of deteriorating control (OR 0.34, 95% CI 0.13 to 0.84), compared with urban residency. Older age (OR 0.95, 95% CI 0.91 to 0.98) was also slightly protective against increased HbA1c. Evacuation and sex were not significant predictors.

CONCLUSIONS

Patients with diabetes who were affected by Japan's triple disaster experienced a deterioration in their glycaemic control following the disasters. The extent of this deterioration was mediated by sociodemographic factors, with rural residence and older age protective against the effects of the disaster on glycaemic control. These results may be indicative of underlying social determinants of health in rural Japan.

Twenty years of socioeconomic inequalities in premature mortality in Barcelona: The influence of population and neighbourhood changes

The objective of this study was to analyse trends in socioeconomic inequalities in premature mortality in Barcelona from 1992 to 2011, accounting for population changes. We conducted a repeated cross-sectional study of the Barcelona population (25-64 years) using generalized linear mixed models for trend analysis, and found that socioeconomic inequalities in premature mortality persisted between neighbourhoods, but tended to diminish. However, the reduction in inequality was related to an increase in the number of foreign-born individuals mainly in socioeconomic disadvantaged neighbourhoods, in which the decrease in premature mortality was more marked. To study trends in geographical inequalities in mortality, it is essential to understand demographic changes occurred in different places related to local levels of deprivation.

Inequalities in mortality by socioeconomic factors and Roma ethnicity in the two biggest cities in Slovakia: a multilevel analysis

Background

The socioeconomic and ethnic composition of urban neighbourhoods may affect mortality, but evidence on Central European cities is lacking. The aim of this study was to assess the associations between socioeconomic and ethnic neighbourhood indicators and the mortality of individuals aged 20–64 years old in the two biggest cities of the Slovak Republic.

Methods

We obtained data on the characteristics of neighbourhoods and districts (educational level, unemployment, income and share of Roma) and on individual mortality of residents aged 20–64 years old, for the two largest cities in the Slovak Republic (Bratislava and Kosice) in the period 2003–2005. We performed multilevel Poisson regression analyses adjusted for age and gender on the individual (mortality), neighbourhood (education level and share of Roma in population) and district levels (unemployment and income).

Results

The proportions of Roma and of low-educated residents were associated with mortality at the neighbourhood level in both cities. Mutually adjusted, only the association with the proportion of Roma remained in the model (risk ratio 1.02; 95 % confidence interval 1.01–1.04). The area indicators – high education, income and unemployment – were not associated with mortality.

Conclusion

The proportion of Roma is associated with early mortality in the two biggest cities in the Slovak Republic.

Spatial inequalities in life expectancy within postindustrial regions of Europe: a cross-sectional observational study

OBJECTIVES

To compare spatial inequalities in life expectancy (LE) in West Central Scotland (WCS) with nine other postindustrial European regions.

DESIGN

A cross-sectional observational study.

SETTING

WCS and nine other postindustrial regions across Europe.

PARTICIPANTS

Data for WCS and nine other comparably deindustrialised European regions were analysed. Male and female LEs at birth were obtained or calculated for the mid-2000s for 160 districts within selected regions. Districts were stratified into two groups: small (populations of between 141 000 and 185 000 people) and large (populations between 224 000 and 352 000). The range and IQR in LE were used to describe within-region disparities.

RESULTS

In small districts, the male LE range was widest in WCS and Merseyside, while the IQR was widest in WCS and Northern Ireland. For women, the LE range was widest in WCS, though the IQR was widest in Northern Ireland and Merseyside. In large districts, the range and IQR in LE was widest in WCS and Wallonia for both sexes.

CONCLUSIONS

Subregional spatial inequalities in LE in WCS are wide compared with other postindustrial mainland European regions, especially for men. Future research could explore the contribution of economic, social and political factors in reducing these inequalities.

Associations between primary healthcare and unplanned medical admissions in Norway: a multilevel analysis of the entire elderly population

OBJECTIVE

To examine if individual risk of unplanned medical admissions (UMAs) was associated with municipality general practitioner (GP) or long-term care (LTC) volume among the entire Norwegian elderly population.

DESIGN

Cross-sectional population-based study.

SETTING

428 of 430 Norwegian municipalities in 2009.

PARTICIPANTS

All Norwegians aged ≥65 years (n=721 915; 56% women-15% of the total population).

MAIN OUTCOME MEASURE

Individual risk of UMA.

RESULTS

Using a multilevel analytical framework, consisting of individuals (N=722 464) nested within municipalities (N=428), nested within local hospital areas (N=52) we found no association between municipality GP or LTC volume and UMAs. However, we found that higher LTC levels of provision were associated with fewer hospitalisations among the older age groups. A modest geographical variability was observed for UMA in adjusted analysis.

CONCLUSIONS

A higher primary healthcare volume was only associated with fewer UMAs among the oldest old in a universally accessible healthcare system.

Group involvement and self-rated health among the Japanese elderly: an examination of bonding and bridging social capital

Background

To date, only a small amount of research on bonding/bridging social capital has separately examined their effects on health though they have been thought to have differential effects on health outcomes. By using a large population-based sample of elderly Japanese people, we sought to investigate the association between bonding and bridging social capital and self-rated health for men and women separately.

Methods

In August 2010, questionnaires were sent to all residents aged ≥65 years in three municipalities in Okayama prefecture (n = 21232), and 13929 questionnaires were returned (response rate: 65.6%). Social capital was measured from survey responses to questions on participation in six different types of groups: a) the elderly club or sports/hobby/culture circle; b) alumni association; c) political campaign club; d) citizen’s group or environmental preservation activity; e) community association; and f) religious organization. Participant perception of group homogeneity (gender, age, and previous occupation) was used to divide social capital into bonding or bridging. Odds ratios (ORs) and 95% confidence intervals (CIs) for poor self-rated health were calculated.

Results

A total of 11146 subjects (4441 men and 6705 women) were available for the analysis. Among men, bonding and bridging social capital were inversely associated with poor self-rated health (high bonding social capital; OR: 0.55, 95% CI: 0.31–0.99; high bridging social capital; OR: 0.62, 95% CI: 0.48–0.81) after adjusting for age, educational attainment, smoking status, frequency of alcohol consumption, overweight, living arrangements, and type-D personality. The beneficial effect among women was more likely limited to bonding social capital (high bonding social capital; OR: 0.34, 95% CI: 0.12–1.00), and the association between bridging social capital and self-rated health was less clear (high bridging social capital; OR: 0.69, 95% CI: 0.44–1.07).

Conclusions

Bonding/bridging social capital could have differential associations with self-rated health among the Japanese elderly depending on the individual’s sex. Considering the lack of consensus on how to measure bonding and bridging social capital, however, we need to carefully assess the generalizability of our findings. Further research is warranted to identify health-relevant dimensions of social capital in different cultural or economic settings.

Mortality risks in relation to occupational category and position among the Japanese working population: the Jichi Medical School (JMS) cohort study

OBJECTIVES

A well-known demographic finding in modern society is the inverse association between socioeconomic status and mortality. The purpose of the study was to examine socioeconomic indicators, such as occupational category (white-collar vs blue -collar) and occupational position (managerial vs non-managerial) as determinants of all -cause, cardiovascular disease (CVD) and cancer mortality in a Japanese working population.

DESIGN

This is a prospective study.

PARTICIPANTS

Data of a baseline survey were collected between 1992 and 1995, and ultimately 6929 Japanese workers aged 65 years and younger (3333 men and 3596 women) from 12 rural communities across Japan were followed until the end of 2005.

MAIN OUTCOME MEASURES

The HRs of death and 95% CIs from all causes were calculated using the Cox proportional hazard model.

RESULTS

Men in blue-collar jobs showed an increased all-cause mortality risk compared with those in white-collar jobs (HR 1.64, 95% CI 1.10 to 2.45). Stratified by occupational category, non-managerial women in blue-collar jobs showed a decreased CVD mortality risk compared with managerial women (HR 0.15, 95% CI 0.03 to 0.81), after adjusting for confounding factors. However, non-managerial women in white-collar jobs showed an increased mortality risk compared with managerial women, although this was not significant (HR 2.34, 95% CI 0.25 to 21.87).

CONCLUSIONS

Socioeconomic disparity according to occupational category was related to the risk of all-cause mortality among Japanese men. There is a potential interaction of occupational category and position in CVD mortality among Japanese women.

A new theory-based social classification in Japan and its validation using historically collected information

Studies of health inequalities in Japan have increased since the millennium. However, there remains a lack of an accepted theory-based classification to measure occupation-related social position for Japan. This study attempts to derive such a classification based on the National Statistics Socio-economic Classification in the UK. Using routinely collected data from the nationally representative Comprehensive Survey of the Living Conditions of People on Health and Welfare, the Japanese Socioeconomic Classification was derived using two variables - occupational group and employment status. Validation analyses were conducted using household income, home ownership, self-rated good or poor health, and Kessler 6 psychological distress (n ≈ 36,000). After adjustment for age, marital status, and area (prefecture), one step lower social class was associated with mean 16% (p < 0.001) lower income, and a risk ratio of 0.93 (p < 0.001) for home ownership. The probability of good health showed a trend in men and women (risk ratio 0.94 and 0.93, respectively, for one step lower social class, p < 0.001). The trend for poor health was significant in women (odds ratio 1.12, p < 0.001) but not in men. Kessler 6 psychological distress showed significant trends in men (risk ratio 1.03, p = 0.044) and in women (1.05, p = 0.004). We propose the Japanese Socioeconomic Classification, derived from basic occupational and employment status information, as a meaningful, theory-based and standard classification system suitable for monitoring occupation-related health inequalities in Japan.

Social and geographical inequalities in suicide in Japan from 1975 through 2005: a census-based longitudinal analysis

Background

Despite advances in our understanding of the countercyclical association between economic contraction and suicide, less is known about the levels of and changes in inequalities in suicide. The authors examined social and geographical inequalities in suicide in Japan from 1975 through 2005.

Methods

Based on quinquennial vital statistics and census data, the authors analyzed the entire population aged 25–64 years. The total number of suicides was 75,840 men and 30,487 women. For each sex, the authors estimated odds ratios (ORs) and 95% credible intervals (CIs) for suicide using multilevel logistic regression models with “cells” (cross-tabulated by age and occupation) at level 1, seven different years at level 2, and 47 prefectures at level 3. Prefecture-level variance was used as an estimate of geographical inequalities in suicide.

Results

Adjusting for age and time-trends, the lowest odds for suicide was observed among production process and related workers (the reference group) in both sexes. The highest OR for men was 2.52 (95% CI: 2.43, 2.61) among service workers, whereas the highest OR for women was 9.24 (95% CI: 7.03, 12.13) among security workers. The degree of occupational inequalities increased among men with a striking change in the pattern. Among women, we observed a steady decline in suicide risk across all occupations, except for administrative and managerial workers and transport and communication workers. After adjusting for individual age, occupation, and time-trends, prefecture-specific ORs ranged from 0.76 (Nara Prefecture) to 1.36 (Akita Prefecture) for men and from 0.79 (Kanagawa Prefecture) to 1.22 (Akita Prefecture) for women. Geographical inequalities have increased primarily among men since 1995.

Conclusions

The present findings demonstrate a striking temporal change in the pattern of social inequalities in suicide among men. Further, geographical inequalities in suicide have considerably increased across 47 prefectures, primarily among men, since 1995.

Geographic inequalities in all-cause mortality in Japan: compositional or contextual?

Background

A recent study from Japan suggested that geographic inequalities in all-cause premature adult mortality have increased since 1995 in both sexes even after adjusting for individual age and occupation in 47 prefectures. Such variations can arise from compositional effects as well as contextual effects. In this study, we sought to further examine the emerging geographic inequalities in all-cause mortality, by exploring the relative contribution of composition and context in each prefecture.

Methods

We used the 2005 vital statistics and census data among those aged 25 or older. The total number of decedents was 524,785 men and 455,863 women. We estimated gender-specific two-level logistic regression to model mortality risk as a function of age, occupation, and residence in 47 prefectures. Prefecture-level variance was used as an estimate of geographic inequalities in mortality, and prefectures were ranked by odds ratios (ORs), with the reference being the grand mean of all prefectures (value  = 1).

Results

Overall, the degree of geographic inequalities was more pronounced when we did not account for the composition (i.e., age and occupation) in each prefecture. Even after adjusting for the composition, however, substantial differences remained in mortality risk across prefectures with ORs ranging from 0.870 (Okinawa) to 1.190 (Aomori) for men and from 0.864 (Shimane) to 1.132 (Aichi) for women. In some prefectures (e.g., Aomori), adjustment for composition showed little change in ORs, while we observed substantial attenuation in ORs in other prefectures (e.g., Akita). We also observed qualitative changes in some prefectures (e.g., Tokyo). No clear associations were observed between prefecture-level socioeconomic status variables and the risk of mortality in either sex.

Conclusions

Geographic disparities in mortality across prefectures are quite substantial and cannot be fully explained by differences in population composition. The relative contribution of composition and context to health inequalities considerably vary across prefectures.

Long working hours and metabolic syndrome among Japanese men: a cross-sectional study

Background

The link between long working hours and health has been extensively studied for decades. Despite global concern regarding metabolic syndrome, however, no studies to date have solely evaluated the relationship between long working hours and that syndrome. We therefore examined the association between long working hours and metabolic syndrome in a cross-sectional study.

Methods

Between May and October 2009, we collected data from annual health checkups and questionnaires from employees at a manufacturing company in Shizuoka, Japan. Questionnaires were returned by 1,601 workers (response rate: 96.2%; 1,314 men, 287 women). After exclusions, including women because of a lack of overtime work, the analysis was performed for 933 men. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for metabolic syndrome. Further, we conducted a stratified analysis by age-group (<40 years vs. ≥40 years).

Results

Metabolic syndrome was identified in 110 workers (11.8%). We observed a positive association between working hours and metabolic syndrome after adjusting for age, occupation, shift work, smoking status, frequency of alcohol consumption, and cohabiting status. Compared with subjects who worked 7–8 h/day, multivariate ORs for metabolic syndrome were 1.66 (95% CI, 0.91–3.01), 1.48 (95% CI, 0.75–2.90), and 2.32 (95% CI, 1.04–5.16) for those working 8–9 h/day, 9–10 h/day, and >10 h/day, respectively. Similar patterns were obtained when we excluded shift workers from the analysis. In age-stratified analysis, the corresponding ORs among workers aged ≥40 years were 2.02 (95% CI, 1.04–3.90), 1.21 (95% CI, 0.53–2.77), and 3.14 (95% CI, 1.24–7.95). In contrast, no clear association was found among workers aged <40 years.

Conclusions

The present study suggests that 10 h/day may be a trigger level of working hours for increased risk of metabolic syndrome among Japanese male workers.