Social class differences in lung cancer mortality: risk factor explanations using two Scottish cohort studies

BACKGROUND: The study investigated differences in lung cancer mortality risk between social classes. METHODS: Twenty years of mortality follow-up were analysed in 7052 men and 8354 women from the Renfrew/Paisley general population study and 4021 working men from the Collaborative study. RESULTS: More manual than non-manual men and women smoked, reported morning phlegm, had worse lung function and lived in more deprived areas. Lung cancer mortality rates were higher in manual than non-manual men and women. Significantly higher lung cancer mortality risks were seen for manual compared to non-manual workers when adjusting for age only and adjustment for smoking reduced these risks to 1.41 (95% CI : 1.12-1.77) for men in the Renfrew/Paisley study, 1.28 (95% CI : 0.94-1.75) for women in the Renfrew/Paisley study and 1.43 (95% CI : 1.02-2.01) for men in the Collaborative study. Adjustment for lung function, phlegm and deprivation category attenuated the risks which were of borderline significance for men in the Renfrew/Paisley study and non significant for women in the Renfrew/Paisley study and men in the Collaborative study. Adding extra socioeconomic variables, available in the Collaborative study only, reduced the difference between the manual and non-manual social classes completely. CONCLUSIONS: There is a difference in lung cancer risk between social classes, in addition to the effect of smoking. This can be explained by poor lung health, deprivation and poor socioeconomic conditions throughout life. As well as anti-smoking measures, reducing socioeconomic inequalities and targeting individuals with poor lung function for help with smoking cessation could help reduce future lung cancer incidence and mortality.     

Inequalities in mortality by social class in men in Barcelona, Spain

Most of the studies of inequalities in mortality carried out in Spain have been ecological, due to the difficulty of obtaining good quality socioeconomic information at individual level. The objective of this study was to describe inequalities in mortality by social class, based on occupation, among men residents of Barcelona in 1993. A representative sample was obtained of men residents of Barcelona who died during the year 1993, aged between 15 and 65 years. It was a retrospective interview given to relatives of the deceased, or other closely related persons. The variables analysed were: age, education level, underlying cause of death, and social class based on occupation (manual and non-manual workers). Rates, relative risks (RRs) and their 95% confidence intervals (95% CIs) are presented by age groups and cause of death. The main results show that among young people, the excess of mortality due to infectious diseases is notable (RR: 1.9; 95% CI: 1.6–2.2), and also due to external causes (RR: 2.1; 95% CI: 1.8–2.4) among manual workers with respect to non-manual workers, mainly due to AIDS and drug overdose. No significant differences were found in mortality due to tumours. For respiratory and cardiovascular causes, there is an increase in mortality in the less favoured social classes, as also occurs for mortality due to diseases of the digestive system, particularly among young manual workers, with an RR: 2.6 (95% CI: 1.5–3.6) compared to non-manual workers. This study shows that it is necessary to continue exploring inequalities in health, but above all it is necessary to implement efficient preventive measures addressed mainly at young people in situations of disadvantage, in order to avoid the excess of avoidable mortality which is found.     

Are social inequalities in mortality in Britain narrowing? Time trends from 1978 to 2005 in a population-based study of older men

OBJECTIVE: To examine whether social inequalities in all-cause and coronary heart disease (CHD) mortality in Britain have reduced between 1978 and 2005. DESIGN: A prospective study of a socioeconomically representative population. SETTING: 24 British towns. PARTICIPANTS: 7735 Men, aged 40-59 years at recruitment in 1978-1980 and followed up until 2005 through the National Health Service Central Register (164 120 person-years). MAIN OUTCOME MEASURES: Relative hazards and absolute risk differences for all-cause and CHD death comparing manual with non-manual social classes, calculated for different calendar periods. RESULTS: 3009 Deaths from all causes (1003 from CHD) occurred during follow-up. The overall hazard ratio (manual versus non-manual) was 1.56 (95% CI 1.45 to 1.69, p<0.001) for all-cause mortality and 1.54 (95% CI 1.35 to 1.76, p<0.001) for CHD mortality. The relative difference between these social groups tended to increase over time. The overall relative increase in hazard ratio comparing manual with non-manual groups over a 20-year calendar period was 1.22 (95% CI 0.83 to 1.80, p = 0.31) for all-cause mortality and 1.75 (95% CI 0.89 to 3.45, p = 0.11) for CHD mortality. The absolute difference in probability of survival to age 65 years between non-manual and manual groups fell from 29% in 1981 to 19% in 2001 for all-cause mortality and from 17% to 7% for CHD mortality. CONCLUSION: Relative differences in all-cause and CHD mortality between manual and non-manual social class groups persisted and may have increased during this period. Absolute differences in mortality between these social groups decreased as a result of falling overall mortality rates. Greater effort is needed to reduce social inequalities in all-cause and CHD mortality in the new millennium.     

Are manual workers at higher risk of death than non-manual employees when living in Swedish municipalities with higher income inequality?

OBJECTIVES: To test the hypothesis that manual workers are at higher risk of death than are non-manual employees when living in municipalities with higher income inequality. DESIGN: Hierarchical regression was used for the analysis were individuals were nested within municipalities according to the 1990 Swedish census. The outcome was all-cause mortality 1992-1998. The income measure at the individual level was disposable family income weighted against composition of family; the income inequality measure used at the municipality level was the Gini coefficient. PARTICIPANTS: The study population consisted of 1 578 186 people aged 40-64 years in the 1990 Swedish census, who were being reported as unskilled or skilled manual workers, lower-, intermediate-, or high-level non-manual employees. RESULTS: There was no significant association between income inequality at the municipality level and risk of death, but an expected gradient with unskilled manual workers having the highest risk and high-level non-manual employees having the lowest. However, in the interaction models the relative risk (RR) of death for high-level non-manual employees was decreasing with increasing income inequality (RR = 0.77; 95% CI, 0.63-0.93), whereas the corresponding risk for unskilled manual workers increased with increasing income inequality (RR = 1.24; 95% CI, 1.06-1.46). The RRs for skilled manual, low- and medium- level non-manual employees were not significant. Controlling for income at the individual level did not substantially alter these findings, neither did potential confounders at the municipality level. CONCLUSIONS: The findings suggest that there could be a differential impact from income inequality on risk of death, dependent on individuals' social position.     

Mortality and social class in Sweden--exploring a new epidemiological tool

Total mortality, mortality from coronary heart disease (CHD), cerebrovascular disease, and other causes of death, were examined for three social groups and ten socio-economic groups in Sweden. The study included all subjects born in the country between 1896 and 1940 who were economically active in 1960-1.9 million men and 0.7 million women. Information on social and socio-economic status, and other social and demographic characteristics, was obtained from the 1960 Census. Information on cause-specific mortality during the period 1961-68 was obtained from a record linkage with the Cause of Death Registry. The analyses were based on 112,469 deaths and 21 million person years at risk. Information on smoking habits was obtained from a sample of 55,000 from the Census population. CHD mortality for women was high among manual workers, SMR = 110 (95% confidence limits 104-117), and low among non-manual workers, SMR = 84 (78-91). CNS-vascular mortality for women was also high among manual workers, SMR = 107 (110-115), and low among non-manual workers, SMR = 89 (82-97). Heavy smoking was more common among non-manual workers in both sexes, which may have contributed to a reverse social class gradient among men, with non-manual male workers being at higher risk for CHD than manual male workers. Farmers (and agricultural workers) generally had a low mortality. Other self-employed men and women had a high total mortality, a high mortality from CHD and CNS-vascular disease--and a high proportion of heavy smokers. There remain differences in mortality between social and socio-economic groups which cannot be explained by smoking habits, age, gender, urbanization, region of residence and martial status.     

Mortality differences by parental social class from childhood to adulthood

STUDY OBJECTIVE: To examine mortality differences by parental social class and cause of death from age 5 to age 34. DESIGN: Register-based follow up study based on census records for 1985 and 1990 linked with death records for the period 1987-95. SETTING AND SUBJECTS: The study covers all males and females in non-manual and manual classes in Finland aged 5-34 years in 1987-95 (8135 deaths). Parental social class is defined on the basis of the occupation of the head of household at the time the child was 0-14 years. MAIN OUTCOME MEASURES: All cause mortality, mortality from diseases, mortality from accidents and violence, and alcohol related mortality during the period 1987-95. MAIN RESULTS: At ages 5-14 there is no systematic gradient in mortality by parental social class. Both absolute and relative differences increase with age. The relative rate of male all cause mortality among manual class descendants at ages 25-29 compared with that of upper non-manual class descendants is 1.60 (95% CI 1.37, 1.86). At ages 30-34 the relative rate among males is 1.95 (95 % CI 1.58, 2.42) and among females 1.47 (95% CI 1. 03, 2.10). Among males alcohol related causes of death account for 70% of the excess mortality of sons of manual class parents compared with sons of upper non-manual class parents at ages 25-34. At ages 25-34, both among females and males, the contribution of diseases to the mortality difference increases. CONCLUSIONS: Parental social class has an impact on mortality after childhood mainly through health related behaviours and lifestyles up to age 34.     

Childhood and adult socioeconomic conditions and 31-year mortality risk in women

Links between low socioeconomic position and poor health are well established. Most previous research, however, has focused on middle-aged males and has relied on limited socioeconomic data, usually measured at one point over the life course. This paper examines all-cause, cardiovascular, and noncardiovascular mortality in women in relation to socioeconomic position at different stages of the life course. Information was collected in 1965, 1974, 1983, and 1994 and included recalled father's occupation and education as a measure of childhood socioeconomic position and the respondent's household income, education and occupation, and spouse's occupation from a sample of 3,087 women participating in the Alameda County Study. Cox regression models were used to estimate hazard ratios for risk of death. Lower childhood socioeconomic position was associated with an increased mortality due to cardiovascular disease (hazard ratio (HR) = 1.29, 95% confidence interval (CI): 1.09, 1.54) but was unrelated to death due to other causes (HR = 0.97, 95% CI: 0.82, 1.15). Overall mortality was higher among women reporting the lowest level of education (HR = 1.17, 95% CI: 0.99, 1.39), but education was most strongly related to noncardiovascular disease-related deaths (HR = 1.41, 95% CI: 1.10, 1.81). Low household income was also associated with higher mortality, for both cardiovascular disease-related (HR = 1.47, 95% CI: 1.14, 1.91) and noncardiovascular disease-related (HR = 1.30, 95% CI: 1.03, 1.63) deaths. Both early and later life indicators of socioeconomic position contribute to increased mortality risk among socioeconomically disadvantaged women, but these effects appear stronger for cardiovascular mortality.     

A nationwide cohort study of educational background and major causes of death among the elderly population in Japan

BACKGROUND: This prospective cohort study examined the association between educational level and major causes of death in Japan. METHOD: A baseline survey was conducted between 1988 and 1990 among 110,792 inhabitants of 45 areas aged 40-79 years. Follow-up surveys were conducted annually and causes of death were identified from death certificates. The analysis was restricted to 16,715 men and 23,284 women. RESULTS: During the follow-up period (377,139 person-years), 6628 deaths were recorded. Individuals with low levels of education had an increased overall risk of death [relative risk (RR)=1.16, 95% confidence interval (CI): 1.08, 1.25, in men; RR=1.26, 95% CI: 1.14, 1.39, in women], cancers (RR=1.17, 95% CI: 1.04, 1.32, in men; RR=1.10, 95% CI: 0.93, 1.30, in women), and death from external causes (RR=1.81, 95% CI: 1.29. 2.54, in men; RR=1.78, 95% CI: 1.18, 2.70, in women). Ischemic heart disease risk was marginally reduced in men with low levels of education (RR=0.77, 95% CI: 0.58, 1.01). CONCLUSIONS: These results show that health inequalities exist in Japan, even though wealth inequalities are relatively low. Social and political initiatives will be needed to correct these inequities between different socioeconomic statuses.     

Correcting for numerator/denominator bias when assessing changing inequalities in occupational class mortality, Australia 1981 -2002

OBJECTIVE: Comparisons of the changing patterns of inequalities in occupational mortality provide one way to monitor the achievement of equity goals. However, previous comparisons have not corrected for numerator/denominator bias, which is a consequence of the different ways in which occupational details are recorded on death certificates and on census forms. The objective of this study was to measure the impact of this bias on mortality rates and ratios over time. METHODS: Using data provided by the Australian Bureau of Statistics, we examined the evidence for bias over the period 1981 -2002, and used imputation methods to adjust for this bias. We compared unadjusted with imputed rates of mortality for manual/non-manual workers. FINDINGS: Unadjusted data indicate increasing inequality in the age-adjusted rates of mortality for manual/non-manual workers during 1981 -2002. Imputed data suggest that there have been modest fluctuations in the ratios of mortality for manual/non-manual workers during this time, but with evidence that inequalities have increased only in recent years and are now at historic highs. CONCLUSION: We found that imputation for missing data leads to changes in estimates of inequalities related to social class in mortality for some years but not for others. Occupational class comparisons should be imputed or otherwise adjusted for missing data on census or death certificates.     

Social mobility, marital status, and mortality risk in an adult life course perspective: the Malmö Preventive Project

AIMS: Adverse social factors predict increased mortality. This study aimed to assess the influence of social class and marital status on mortality, adding an adult life course perspective. METHODS: In total, 32,907 males and 20,204 females were evaluated based on census data in Malm?, Sweden. Of these subjects, 22,444 males and 10,902 females also took part in health screening. The main outcomes were all-cause and cause-specific mortality rates in subgroups based on social class and marital status, either measured once or repeatedly in adult life. Results were based on a total of 522,807 years of follow-up in men (5,761 deaths) and 239,815 in women (1,354 deaths). RESULTS: Total and cardiovascular mortality were significantly higher in manual male employees with age-adjusted risk ratios (RR) of 1.7 (95% CI 1.5-1.9) and 1.6 (1.3-2.0) in skilled manual workers, and 2.0 (1.7-2.2) and 1.9 (1.6-2.3) in unskilled manual workers, compared with high-level non-manual employees. The differences remained after adjustment for baseline risk factors and prevalent cardiovascular disease, and were similar for women. Increased mortality risk was also documented for subjects who were divorced or unmarried (adjusted for social class), as well as being downward socially mobile or in a permanent low social class (manual) position. CONCLUSIONS: Social class based on occupation, either measured once or repeatedly in adult life, is associated with marked differences in mortality risk in middle-aged subjects. People who remain married/cohabiting or remarry are at lower risk of early death than people who remain unmarried or divorced.     

Socioeconomic and demographic differences in exposure to environmental tobacco smoke at work: the Scania Public Health Survey 2000

BACKGROUND: A study was undertaken to investigate the sociodemographic distribution of workplace exposure to environmental tobacco smoke (ETS) in a Swedish working population sample. METHODS: 8,270 individuals were assessed by questionnaire in the Scania Public Health Survey. The influence of sociodemographic factors on ETS exposure at work was investigated by multivariable regression analysis. RESULTS: Individuals under 25 years old were at highest risk of ETS exposure. Male skilled manual workers and female unskilled manual workers had higher adjusted odds ratios (OR 4.0, 95% CI: 3.1-5.3 and OR 3.2, 95% CI: 2.2-4.7, respectively) of ETS exposure than non-manual high-level employees. CONCLUSIONS: ETS should be recognized as a factor contributing to health inequalities. Women of childbearing age need protective strategies.     

Inequalities in mental health in the working population.

Objectives: To analyze inequalities in mental health in the working population by gender and professional qualifications and to identify psychosocial risk factors and employment conditions related to the mental health of this population. Methods: We performed a cross-sectional study using data from the Barcelona Health Survey 2000. The working population aged 16-64 years (2322 men and 1836 women) was included. Mental health was measured with the General Health Questionnaire (GHQ-12). Adjusted odds ratios (aOR) and their 95% confidence intervals (CI) were calculated by means of multivariate logistic regression models separated by job qualifications and gender. Results: The prevalence of poor mental health ranged from 8% among men working in non-manual occupations to 19% in women working in manual jobs. Women were more likely to report poor mental health status than men, although sex differences were greater among manual workers (aOR = 2.26; 95%CI, 1.68-3.05 for women compared to men in the same group). Differences according to qualifications were found among women only (aOR = 1.58 [95%CI, 1.22-2.05] for women working in manual jobs compared to those working in non-manual jobs), while no differences were found among men according to qualifications. Psychosocial risk factors were associated with mental health: demand was associated in all groups, autonomy only in non-manual occupations, and social support only in the most highly qualified working women. Employment conditions such as working a split shift (working day with a long lunch break) or having a temporary contract were associated with mental health in manual occupations only. Conclusions: Mental health among the working population is related to professional qualifications and gender. Women are at greater risk than men, especially those working in manual occupations. Psychosocial occupational factors are related to mental health status, showing different patterns depending on gender and professional qualifications.     

Irregular menstruation according to occupational status

This cross-sectional study explored associations of irregular menstruation with occupational characteristics, using secondary analyses of data from 4,731 women aged 19–54 years, collected from a nationally representative sample, the Korea National Health and Nutrition Examination Survey-V during 2010–2012. The associations between irregular menstruation and occupation were explored using multiple logistic regression. Compared to non-manual workers, service/sales workers had a greater odds of irregular menstruation (adjusted odds ratio [aOR]: 1.44; 95percent confidence interval [CI]: 1.04–1.99) as did manual workers and unemployed women (aOR: 1.56; 95percent CI: 1.10–2.22, aOR: 1.46; 95percent CI: 1.14–1.89, respectively). Compared to regular workers, temporary workers and unemployed women had aORs of 1.52 (95percent CI: 1.08–2.13) and 1.33 (95percent CI: 1.05–1.69), respectively. Also, when compared to full-time workers, part-time workers and unemployed women had greater odds of irregular menstruation (aOR: 1.41; 95percent CI: 1.00–2.00 and aOR: 1.29; 95percent CI: 1.03–1.63, respectively). Furthermore, compared to daytime workers, shift workers and unemployed women had greater odds irregular menstruation (aOR: 1.39; 95percent CI: 1.03–1.88 and aOR: 1.28; 95percent CI: 1.04–1.59, respectively). Women with these occupational characteristics should be screened for early diagnosis and intervention for irregular menstruation.     

Change in male and female life expectancy by social class: decomposition by age and cause of death in Finland 1971-95.

STUDY OBJECTIVE: To quantify the contribution of different causes of death and age groups for trends in life expectancy for two major social classes. DESIGN AND SETTING: Prospective study of mortality in Finland among all over 35 year old men and women. Baseline social class (manual/non-manual) was from the 1970, 1975, 1980, 1985 and 1990 census records, and follow up was by computerised record linkage to death certificates for 1971-1995. MAIN RESULTS: From the early 1970s to the early 1990s life expectancy at age 35 increased by about five and four years among Finnish men and women respectively, with largest gains among 55-74 year old men and 65-84 year old women. Life expectancy increase was 5.1 years among non-manual and 3.8 years among manual men; corresponding figures for women were 3.6 and 3.0 years. In the 1980s, when differences in life expectancy increased most rapidly, decline in cardiovascular disease mortality was more rapid in the non-manual than the manual class. Furthermore, increasing mortality for alcohol associated causes, "other diseases", and accidents and violence were most prominent in the manual class. CONCLUSIONS: Explanations of increasing social inequalities in mortality that are based on one underlying factor are difficult to reconcile with the variability in the cause specific trends in social inequalities in mortality. The contribution of older ages to social inequalities in mortality should be more widely recognised.     

Successful Aging and Mortality Risk: The Korean Longitudinal Study of Aging (2006-2014)

ObjectivesThe aim of this study is to examine the association of successful aging with mortality and further find gender differences in the effect of components of successful aging on mortality risks.DesignRetrospective cohort study.Setting and participantsA total of 3848 adults aged 65 and older from the Korean Longitudinal Study of Aging (2006-2014) data.MeasuresSuccessful aging was defined as success in the following 7 components: absence of major disease, no depression, no freedom from disability, high cognitive and physical function, active social engagement, and satisfaction with life. All-cause mortality was measured by death certificate and family interview.ResultsIn both genders, the mortality rate was higher in the older adults who did not achieve successful aging than in their counterparts (men: hazard ratio [HR] = 1.69, 95% confidence interval [CI] 1.18-2.43; and women: HR = 2.37, 95% CI 1.21-4.63). All components of no successful aging were associated with an increased risk of mortality except for no satisfaction with life in females. Mortality rates were predominant in major disease (HR = 1.86, 95% CI 1.54-2.25) and depressive symptoms (HR = 1.62, 95% CI 1.26-2.10) in males, and disability (HR = 2.08, 95% CI 1.68-2.57) and low physical functioning (HR = 2.31, 95% CI 1.79-2.98) were predominant in females.Conclusion/ImplicationWe found that older Koreans who did not achieve successful aging had a higher risk of all-cause mortality than successful agers. There were gender differences in mortality risks across all components of successful aging.     

Ethnic inequalities in age- and cause-specific mortality in The Netherlands

BACKGROUND: By describing ethnic differences in age- and cause-specific mortality in The Netherlands we aim to identify factors that determine whether ethnic minority groups have higher or lower mortality than the native population of the host country. METHODS: We used data for 1995-2000 from the municipal population registers and cause of death registry. All inhabitants of The Netherlands were included in the study. The mortality of people who themselves or whose parent(s) were born in Turkey, Morocco, Surinam, or the Dutch Antilles/Aruba was compared with that of the native Dutch population. Mortality differences were estimated by Poisson regression analyses and by directly standardized mortality rates. RESULTS: Compared with native Dutch men, mortality was higher among Turkish (relative risk [RR] = 1.21, 95% CI: 1.16, 1.26), Surinamese (RR = 1.24, 95% CI: 1.19, 1.29), and Antillean/Aruban (RR = 1.25, 95% CI: 1.15, 1.36) males, and lower among Moroccan males (RR = 0.85, 95% CI: 0.81, 0.90). Among females, inequalities in mortality were small. In general, mortality differences were influenced by socio-economic and marital status. Most minority groups had a high mortality at young ages and low mortality at older ages, a high mortality from ill-defined conditions (which is related to mortality abroad) and external causes, and a low mortality from neoplasms. Cardiovascular disease mortality was low among Moroccan males (RR = 0.51, 95% CI: 0.44, 0.59) and high among Surinamese males (RR = 1.13, 95% CI: 1.05, 1.21) and females (RR = 1.14, 95% CI: 1.06, 1.23). Homicide mortality was elevated in all groups. CONCLUSION: Socio-economic factors and marital status were important determinants of ethnic inequalities in mortality in The Netherlands. Mortality from cardiovascular diseases, homicide, and mortality abroad were of particular importance for shifting the balance from high towards low all-cause mortality.     

Mortality of lead smelter workers

To examine patterns of death in lead smelter workers, a retrospective analysis of mortality was conducted in a cohort of 1,987 males employed between 1940 and 1965 at a primary lead smelter in Idaho. Overall mortality was similar to that of the United States white male population (standardized mortality ratio (SMR) = 98). Excess mortality, however, was found from chronic renal disease (SMR = 192; confidence interval (CI) = 88-364), and the risk of death from renal disease increased with increasing duration of employment, such that after 20 years employment, the standardized mortality ratio reached 392 (CI = 107-1,004). Excess mortality was also noted for nonmalignant respiratory disease (SMR = 187, CI = 128-264). Eight of 32 deaths in this category were caused by silicosis; at least five workers who died of silicosis had been miners for a part of their lives. An additional 11 deaths resulted from tuberculosis (SMR = 139; CI = 69-249); in six of these cases, silicosis was a contributory cause of death. Cancer mortality was not increased overall (SMR = 95; CI = 78-114). An increase, however, was noted for deaths from kidney cancer (six cases; SMR = 204; CI = 75-444). Finally, excess mortality was noted for injuries (SMR = 138; CI = 104-179); 13 (23%) of the 56 deaths in this category were caused by mining injuries. The data from this study are consistent with previous reports of increased mortality from chronic renal disease in persons exposed occupationally to lead.     

Cohort mortality study of Swedish pulp and paper mill workers-nonmalignant diseases

OBJECTIVES: The aim of this study was to determine mortality among pulp and paper mill workers according to the main mill pulping process, department, and gender, particular reference being given to diseases of the circulatory and respiratory systems. METHODS: The cohort of 18 163 men and 2 291 women employed between 1939 and 1999 and with >1 year of employment was followed for mortality from 1952 to 2001 (acute myocardial infarction from 1969). Standardized mortality ratios (SMR) with 95% confidence intervals (95% CI) were estimated by comparing the observed number of deaths with the expected number for the entire Swedish population. Exposure was assessed from personnel files in the mills. Data from an exposure measurement database are also presented. RESULTS: There were 5898 deaths in the cohort. Total mortality had an SMR of 1.02 (95% CI 0.98-1.06) for the men in the sulfate mills and an SMR of 0.93 (95% CI 0.90-0.97) for the men in the sulfite mills. Mortality from acute myocardial infarction was increased among the men in both the sulfate and sulfite mills [SMR 1.22 (95% CI 1.12-1.32) and SMR 1.11 (95% CI 1.02-1.21), respectively] and by department in sulfate pulping (SMR 1.29, 95% CI 1.07-1.54), paper production (SMR 1.26, 95% CI 1.06-1.49), and maintenance (SMR 1.16, 95% CI 1.02-1.30). Mortality from cerebrovascular disease, diabetes mellitus, and nonmalignant respiratory diseases was not increased. CONCLUSIONS: Death from acute myocardial infarction, but not cerebrovascular diseases, was increased in this cohort and was probably related to a combination of different occupational exposures (eg, dust, sulfur compounds, shift work, and noise).     

Widening Socioeconomic Inequalities in Smoking in Japan, 2001–2016

BackgroundJapan is one of the world’s largest tobacco epidemic countries but few studies have focused on socioeconomic inequalities. We aimed to examine whether socioeconomic inequalities in smoking have reduced in Japan in recent times.MethodsWe analyzed data from the Comprehensive Survey of Living Conditions, a large nationally representative survey conducted every 3 years (n ≈ 700,000 per year) in Japan, during 2001–2016. Age-standardized smoking prevalence was computed based on occupational class and educational level. We calculated smoking prevalence difference (PD) and ratio (PR) of (a) manual workers versus upper non-manual workers and (b) low versus high educational level. The slope index of inequality (SII) and relative index inequality (RII) by educational level were used as inequality measures.ResultsOverall smoking prevalence (25–64 years) decreased from 56.0% to 38.4% among men and from 17.0% to 13.0% among women during 2001–2016. The PD between manual and upper non-manual workers (25–64 years) increased from 11.9% (95% confidence interval [CI], 11.0–12.9%) to 14.6% (95% CI, 13.5–15.6%) during 2001–2016. In 2016, smoking prevalence (25–64 years) for low, middle, and highly educated individuals were 57.8%, 43.9%, and 27.8% for men, and 34.7%, 15.9%, and 5.6% for women, respectively. SII and RII by educational level increased among both sexes. Larger socioeconomic differences in smoking prevalence were observed in younger generations, which suggests that socioeconomic inequalities in smoking evolve in a cohort pattern.ConclusionsSocioeconomic inequalities in smoking widened between 2001 and 2016 in Japan, which indicates that health inequalities will continue to exist in near future.Key words: epidemiology, smoking, socioeconomic factors, Japan, trends     

Body mass index and mortality in a middle-aged Japanese cohort

BACKGROUND: The relative risk of mortality in low and high body mass index (BMI) categories in various ethnic groups remains a controversial subject. METHODS: To examine the relationship between BMI and mortality, a population-based prospective cohort study was conducted in two areas of Gunma Prefecture, Japan, in 1993. A total of 5,554 men and 5,827 women aged 40-69 years completed a self-administered questionnaire and were followed up until the year 2000. The hazard ratios (HRs) were estimated by the Cox proportional hazards model for different BMI classes. RESULTS: During the seven year follow-up period, 329 men and 147 women died. As compared with those in the reference BMI category (22.0-24.9 kg/m(2)), men and women in the lowest BMI category (<18.5 kg/m(2)) had a HR (95% confidence interval [CI]) of death from all-causes of 2.66 (1.59-4.46) and 3.14 (1.38-7.13), respectively, and women in the highest BMI category (28.0+ kg/m(2)) had a HR of death of 3.25 (1.48-7.15), after adjusting for all possible confounding factors including smoking and after excluding deaths occurring during the first three years of follow-up. CONCLUSION: In this prospective study of a Japanese cohort consisting of subjects ranging in age from 40 to 69 years, the curve depicting the relationship between BMI and all-cause mortality was L-shaped in men and U-shaped in women.