Community-level income inequality and mortality in Québec, Canada

The association between nation-level social and economic indices and suicide rates: A pilot study

Ever since the pioneering work of Emile Durkheim, it has been known that regional or national suicide rates can be influenced by a variety of social and economic factors. Recent research has found a robust association between two country-level economic indices-gross national product and unemployment rate-and suicide rates, particularly in men. However, the association between other country-level social indices-such as measures of social integration, inequality, environmental preservation and political freedom-and suicide rates has not been studied at the cross-national level. In the current study, national suicide rates for men and women were examined in relation to seven indices measuring subjective wellbeing, sustainable development, type of political regime, economic and gender inequality, and social capital. It was found that the Happy Planet Index, a composite measure of subjective wellbeing and sustainable development, was negatively associated with suicide rates independent of gender, and even after adjusting for possible confounding factors. Economic inequality was associated with suicide in men, and social capital was associated with suicide in women. Moreover, the strength and direction of the associations observed between socioeconomic indices and suicide varied across income groups. These results highlight the need for a closer evaluation of the link between large-scale ("macro") social factors and individual ("micro") psychological factors, as well as the importance of integrating these factors into suicide prevention programmes at the national level.

Investigating the association between income inequality in youth and deaths of despair in Canada: a population-based cohort study from 2006 to 2019

BACKGROUND

Deaths due to suicide, drug overdose and alcohol-related liver disease, collectively known as 'deaths of despair', have been markedly increasing since the early 2000s and are especially prominent in young Canadians. Income inequality has been linked to this rise in deaths of despair; however, this association has not yet been examined in a Canadian context, nor at the individual level or in youth. The study objective was to examine the association between income inequality in youth and deaths of despair among youth over time.

METHODS

We conducted a population-based longitudinal study of Canadians aged 20 years or younger using data from the Canadian Census Health and Environment Cohorts. Baseline data from the 2006 Canadian Census were linked to the Canadian Vital Statistics Database up to 2019. We employed multilevel survival analysis models to quantify the association between income inequality in youth and time-to deaths of despair.

RESULTS

The study sample included 1.5 million Canadians, representing 7.7 million Canadians between the ages of 0 and 19 at baseline. Results from the weighted, adjusted multilevel survival models demonstrated that income inequality was associated with an increased hazard of deaths of despair (adjusted HR (AHR) 1.35; 95% CI 1.04 to 1.75), drug overdose (AHR 2.38; 95% CI 1.63 to 3.48) and all-cause deaths (AHR 1.10; 95% CI 1.04 to 1.18). Income inequality was not significantly associated with suicide deaths (AHR 1.23, 95% CI 0.93 to 1.63).

CONCLUSION

The results show that higher levels of income inequality in youth are associated with an increased hazard of all-cause death, deaths of despair and drug overdose in young Canadians. This study is the first to reveal the association between income inequality and deaths of despair in youth and does so using a population-based longitudinal cohort involving multilevel data. The results of this study can inform policies related to income inequality and deaths of despair in Canada.

Effect of Income Inequality on Health in Quebec: New Insights from Panel Data

We investigated the relationship between income inequality and all-cause mortality in 87 regional county municipalities (RCMs) of Quebec (Canada) while accounting for time lags and effects of other socioeconomic variables. We presumed to be true that income inequality entails stress and depression. Thus, these phenomena were tested as mediating factors. The data used consist of eight (8) area-based chronological variables: mortality rate, Gini index, disposable income, criminality rate, number of physicians, density of population, and the proportion of people reporting feeling stressed or depressed. The association between income inequality and mortality was analyzed using the generalized method of moments (GMM) approach with local fixed effects to control unobservable characteristics. Our results show that higher income inequality led to a significant increase of mortality rate with a time lag of 5 years when socioeconomic characteristics were held constant. As expected, households’ disposable income and mortality rate were negatively associated. Moreover, mortality rate was positively associated with population density and negatively associated with the number of physicians. Finally, only depression showed the potential to act as a mediating factor. Based on our findings, we suggest that, over time, income inequality, by amplifying depression phenomena, increases the mortality rate in Quebec’s RCMs.

Income-related inequality in completed suicide across the provinces of Iran

OBJECTIVES

The aim of this study was to measure income-related inequality in completed suicide across the provinces of Iran.

METHODS

This ecological study was performed using data from the Urban and Rural Household Income and Expenditure Survey-2010 conducted by the Iranian Center of Statistics, along with data on completed suicide from the Iranian Legal Medicine Organization in 2012. We calculated the Gini coefficient of per capita income and the completed suicide rate, as well as the concentration index for per capita income inequality in completed suicide, across the provinces of Iran.

RESULTS

The Gini coefficients of per capita income and the completed suicide rate in the provinces of Iran were 0.10 (95% confidence interval [CI], 0.06 to 0.13) and 0.34 (95% CI, 0.21 to 0.46), respectively. We found a trivial decreasing trend in the completed suicide incidence rate according to income quintile. The poorest-to-richest ratio in the completed suicide rate was 2.01 (95% CI, 1.26 to 3.22). The concentration index of completed suicide in the provinces of Iran was -0.12 (95% CI, -0.30 to 0.06).

CONCLUSIONS

This study found that lower income might be considered as a risk factor for completed suicide. Nonetheless, further individual studies incorporating multivariable analysis and repeated cross-sectional data would allow a more fine-grained analysis of this phenomenon.

Tract- and county-level income inequality and individual risk of obesity in the United States

OBJECTIVES

We tested three alternative hypotheses regarding the relationship between income inequality and individual risk of obesity at two geographical scales: U.S. Census tract and county.

METHODS

Income inequality was measured by Gini coefficients, created from the 2000 U.S. Census. Obesity was clinically measured in the 2003-2008 National Health and Nutrition Examination Survey (NHANES). The individual measures and area measures were geo-linked to estimate three sets of multi-level models: tract only, county only, and tract and county simultaneously. Gender was tested as a moderator.

RESULTS

At both the tract and county levels, higher income inequality was associated with lower individual risk of obesity. The size of the coefficient was larger for county-level Gini than for tract-level Gini; and controlling income inequality at one level did not reduce the impact of income inequality at the other level. Gender was not a significant moderator for the obesity-income inequality association.

CONCLUSIONS

Higher tract and county income inequality was associated with lower individual risk of obesity, indicating that at least at the tract and county levels and in the context of cross-sectional data, the public health goal of reducing the rate of obesity is in line with anti-poverty policies of addressing poverty through mixed-income development where neighborhood income inequality is likely higher than homogeneous neighborhoods.

The association between income inequality and all-cause mortality across urban communities in Korea

BACKGROUND

Korea has achieved considerable economic growth more rapidly than most other countries, but disparities in income level have increased. Therefore, we sought to assess the association between income inequality and mortality across Korean cities.

METHODS

Data on household income were obtained from the 2010-2012 Korean Community Health Survey and data on all-cause mortality and other covariates were obtained from the Korean Statistical Information Service. The Gini coefficient, Robin Hood index, and income share ratio between the 80th and 20th percentiles of the distribution were measured for each community. After excluding communities affected by changes in administrative districts between 2010 and 2012, a total of 157 communities and 172,398 urban residents were included in the analysis.

RESULTS

When we graphed income inequality measures versus all-cause mortality as scatter plots, the R square values of the regression lines for GC, RHI, and 80/20 ratios relative to mortality were 0.230, 0.238, and 0.152, respectively. After adjusting for other covariates and median household income, mean all-cause mortality increased significantly with increasing GC (P for trend = 0.014) and RHI (P for trend = 0.031), and increased marginally with 80/20 ratio (P for trend = 0.067).

CONCLUSIONS

Our data demonstrate that income inequality measures are significantly associated with all-cause mortality rate after adjustment for covariates, including median household income across urban communities in Korea.

Does Social Context Matter? Income Inequality, Racialized Identity, and Health Among Canada's Aboriginal Peoples Using a Multilevel Approach

OBJECTIVES

Debates surrounding the importance of social context versus individual level processes have a long history in public health. Aboriginal peoples in Canada are very diverse, and the reserve communities in which they reside are complex mixes of various cultural and socioeconomic circumstances. The social forces of these communities are believed to affect health, in addition to individual level determinants, but no large scale work has ever probed their relative effects. One aspect of social context, relative deprivation, as indicated by income inequality, has greatly influenced the social determinants of health landscape. An investigation of relative deprivation in Canada's Aboriginal population has never been conducted. This paper proposes a new model of Aboriginal health, using a multidisciplinary theoretical approach that is multilevel.

METHODS

This study explored the self-rated health of respondents using two levels of determinants, contextual and individual. Data were from the 2001 Aboriginal Peoples Survey. There were 18,890 Registered First Nations (subgroup of Aboriginal peoples) on reserve nested within 134 communities. The model was assessed using a hierarchical generalized linear model.

RESULTS

There was no significant variation at the contextual level. Subsequently, a sequential logistic regression analysis was run. With the sole exception culture, demographics, lifestyle factors, formal health services, and social support were significant in explaining self-rated health.

CONCLUSIONS

The non-significant effect of social context, and by extension relative deprivation, as indicated by income inequality, is noteworthy, and the primary role of individual level processes, including the material conditions, social support, and lifestyle behaviors, on health outcomes is illustrated. It is proposed that social structure is best conceptualized as a dynamic determinant of health inequality and more multilevel theoretical models of Aboriginal health should be developed and tested.

Making the invisible visible: are health social workers addressing the social determinants of health?

This study explored the ways in which health social workers (HSW) address the social determinants of health (SDH) within their social work practice. Social workers (n = 54) employed at major hospitals across Toronto had many years of practice in health care (M = 11 years; SD = 10.32) and indicated that SDH were a top priority in their daily work; with 98% intentionally intervening with at least one and 91% attending to three or more. Health care services were most often addressed (92%), followed by housing (72%), disability (79%), income (72%), and employment security (70%). Few HSW were tackling racism, Aboriginal status, gender, or social exclusion in their daily practice.

Suicide rates and income in São Paulo and Brazil: a temporal and spatial epidemiologic analysis from 1996 to 2008

BACKGROUND

In a classical study, Durkheim noted a direct relation between suicide rates and wealth in the XIX century France. Since that time, several studies have verified this relationship. It is known that suicide rates are associated with income, although the direction of this association varies worldwide. Brazil presents a heterogeneous distribution of income and suicide across its territory; however, evaluation for an association between these variables has shown mixed results. We aimed to evaluate the relationship between suicide rates and income in Brazil, State of São Paulo (SP), and City of SP, considering geographical area and temporal trends.

METHODS

Data were extracted from the National and State official statistics departments. Three socioeconomic areas were considered according to income, from the wealthiest (area 1) to the poorest (area 3). We also considered three regions: country-wide (27 Brazilian States and 558 Brazilian micro-regions), state-wide (645 counties of SP State), and city-wide (96 districts of SP city). Relative risks (RR) were calculated among areas 1, 2, and 3 for all regions, in a cross-sectional approach. Then, we used Joinpoint analysis to explore the temporal trends of suicide rates and SaTScan to investigate geographical clusters of high/low suicide rates across the territory.

RESULTS

Suicide rates in Brazil, the State of SP, and the city of SP were 6.2, 6.6, and 5.4 per 100,000, respectively. Taking suicide rates of the poorest area (3) as reference, the RR for the wealthiest area was 1.64, 0.88, and 1.65 for Brazil, State of SP, and city of SP, respectively (p for trend <0.05 for all analyses). Spatial cluster of high suicide rates were identified at Brazilian southern (RR = 2.37), state of SP western (RR = 1.32), and city of SP central (RR = 1.65) regions. A direct association between income and suicide were found for Brazil (OR = 2.59) and the city of SP (OR = 1.07), and an inverse association for the state of SP (OR = 0.49).

CONCLUSIONS

Temporospatial analyses revealed higher suicide rates in wealthier areas in Brazil and the city of SP and in poorer areas in the State of SP. We further discuss the role of socioeconomic characteristics for explaining these discrepancies and the importance of our findings in public health policies. Similar studies in other Brazilian States and developing countries are warranted.

Mortality among adults: gender and socioeconomic differences in a Brazilian city

Background

Population groups living in deprived areas are more exposed to several risk factors for diseases and injuries and die prematurely when compared with their better-off counterparts. The strength and patterning of the relationships between socioeconomic status and mortality differ depending on age, gender, and diseases or injuries. The objective of this study was to identify the magnitude of social differences in mortality among adult residents in a city of one million people in Southeastern Brazil in 2004-2008.

Methods

Forty-nine health care unit areas were classified into three homogeneous strata using 2000 Census small-area socioeconomic indicators. Mortality rates by age group, sex, and cause of death were calculated for each socioeconomic stratum. Mortality rate ratios (RR) and 95% confidence intervals were estimated for the low and middle socioeconomic strata compared with the high stratum.

Results

In general, age-specific mortality rates showed a social gradient of increasing risks of death with decreasing socioeconomic status. The highest mortality rate ratios between low and high strata were observed in the 30-39 age group for males (RR = 1.74, 95% CI 1.59-1.89), and females (RR = 1.90, 95% CI 1.65-2.15). Concerning specific diseases and injuries, the greatest inequalities between low and high strata were found for homicides (RR = 2.44, 95% CI 2.27-2.61) and traffic accidents (RR = 1.64, 95% CI 1.45-1.83) among males. For women, the highest inequalities between the low and high strata were for chronic respiratory diseases (RR = 2.19, 95% CI 1.94-2.45) and acute myocardial infarction (RR = 1.93, 95% CI 1.79-2.07). Only breast cancer showed a reversed social gradient (RR = 0.70, 95% CI 0.48-0.92). Inequalities in circulatory and respiratory diseases mortality were greater among females than among males.

Conclusions

Substandard living conditions are related to unhealthy behaviors, as well as difficulties in accessing health care. Therefore, the Brazilian Health System (SUS) must ensure greater access to primary and hospital care, and develop programs that promote healthier lifestyles among vulnerable groups to reduce social inequalities in mortality. Moreover, because deaths from external causes are concentrated in poor areas, cooperative and coordinated intersectoral actions should be taken to combat the deadly violence cycle.

Does the socioeconomic context explain both mortality and income inequality? Prospective register-based study of Norwegian regions

Background

Studies from various countries have observed worse population health in geographical areas with more income inequality. The psychosocial interpretation of this association is that large income disparities are harmful to health because they generate relative deprivation and undermine social cohesion. An alternative explanation contends that the association between income inequality and ill health arises because the underlying social and economic structures will influence both the level of illness and disease and the size of income differences. This paper examines whether the observed association between mortality and income inequality in Norwegian regions can be accounted for by the socioeconomic characteristics of the regions.

Methods

Norwegian register data covering the entire population were utilised. An extensive set of contextual and individual predictors were included in multilevel Poisson regression analyses of mortality 1994-2003 among 1.6 millions individuals born 1929-63, distributed across 35 residential regions.

Results

Mean income, composition of economic branches, and percentage highly educated in the regions were clearly connected to the level of income inequality. These social and economic characteristics of the regions were also markedly related to regional mortality levels, after adjustment for population composition, i.e., the individual-level variables. Moreover, regional mortality was significantly higher in regions with larger income disparities. The regions' social and economic structure did not, however, account for the association between regional income inequality and mortality. A distinct independent effect of income inequality on mortality remained after adjustment for regional-level social and economic characteristics.

Conclusions

The results indicate that the broader socioeconomic context in Norwegian regions has a substantial impact both on mortality and on the level of income disparities. However, the results also suggest, in a way compatible with the psychosocial interpretation, that on top of the general socioeconomic influences, a higher level of income inequality adds independently to higher mortality levels.

Previous publication

This article is a reworked version of the study 'Er inntektsforskjeller dødelige?' [Are income inequalities lethal?] which was published in Norwegian in Tidsskrift for velferdsforskning [Journal for welfare research], Vol. 13 (4), 2010.

Sex, age, deprivation and patterns in life expectancy in Quebec, Canada: a population-based study

BACKGROUND

Little research has evaluated disparities in life expectancy according to material deprivation taking into account differences across the lifespan between men and women. This study investigated age- and sex-specific life expectancy differentials related to area-level material deprivation for the province of Québec, Canada from 1989-2004.

METHODS

Age- and sex-specific life expectancy across the lifespan was calculated for three periods (1989-1992, 1995-1998, and 2001-2004) for the entire Québec population residing in 162 community groupings ranked according to decile of material deprivation. Absolute and relative measures were calculated to summarize differences between the most and least deprived deciles.

RESULTS

Life expectancy differentials between the most and least deprived deciles were greatest for men. Over time, male differentials increased for age 20 or more, with little change occurring at younger ages. For women, differentials increased across the lifespan and were comparable to men at advanced ages. Despite gains in life expectancy among men relative to women, differentials between men and women were greater for most deprived relative to least deprived deciles.

CONCLUSIONS

Similar to the US, differentials in life expectancy associated with area-level material deprivation increased steadily in Québec from 1989-2004 for males and females of all ages. Differentials were comparable between men and women at advanced ages. Previous research indicating that life expectancy differentials between most and least deprived areas are greater in men may be due to a focus on younger age groups.

Socio-economic inequalities in suicide attempts and suicide mortality in Québec, Canada, 1990-2005

OBJECTIVES

Little research has evaluated changes in the association between area deprivation and suicidal behaviour over time. This study investigated patterns in suicide attempts and suicide mortality according to material deprivation in the province of Québec, Canada between 1990 and 2005.

STUDY DESIGN

Ecological analysis.

METHODS

Data on suicide attempts were extracted from the hospital discharge summary database (n=47,516) and data on suicides were extracted from the Québec death file (n=20,851). Gender- and age-specific (10-24, 25-44, 45-64 and > or = 65 years) suicide attempt and mortality rates were calculated for four time periods (1990-1993, 1994-1997, 1998-2001 and 2002-2005) for the entire Québec population aged 10 years and older residing in 162 communities ranked by decile of material deprivation. Absolute and relative measures of inequality were calculated to summarize differences between the most and least materially deprived areas. Commonly used methods of suicidal behaviour were examined.

RESULTS

Differentials in suicide attempt hospitalization between the most and least deprived areas were present for all age groups, and these decreased slightly among males and increased among females over time. Inequalities in suicide attempts were greatest among young adults (age 25-44 years) for both genders, and were smallest among the elderly (> or = 65 years). For suicide mortality, differentials increased among females but not males; these differentials were greatest among males and 25-44 year olds, and smallest among the elderly. Differentials in commonly used methods were evident for poisoning hospitalizations in both genders and for hanging deaths among males.

CONCLUSIONS

In Québec, differences in suicide attempts and mortality between the most and least materially deprived areas persisted or even increased over time. Inequalities were more pronounced for suicide attempts than for suicide mortality, and were greatest among adults of working age. Strategies to reduce socio-economic differences in suicidal behaviour may be important.