Ecological association between suicide rates and indices of deprivation in the north west region of England: the importance of the size of the administrative unit

Association Between COVID-19 and Self-Harm: Nationwide Retrospective Ecological Spatiotemporal Study in Metropolitan France

Background

The COVID-19 pandemic has not been associated with increases in suicidal behavior at the national, regional, or county level. However, previous studies were not conducted on a finer scale or adjusted for ecological factors.

Objective

Our objective was to assess the fine-scale spatiotemporal association between self-harm and COVID-19 hospitalizations, while considering ecological factors.

Methods

Using the French national hospital discharge database, we extracted data on hospitalizations for self-harm of patients older than 10 years (from 2019 to 2021) or for COVID-19 (from 2020 to 2021) in metropolitan France. We first calculated monthly standardized incidence ratios (SIRs) for COVID-19 between March 2020 and December 2021, using a Besag, York, and Mollié spatiotemporal model. Next, we entered the SIRs into an ecological regression in order to test the association between hospital admissions for self-harm and those for COVID-19. Lastly, we adjusted for ecological variables with time lags of 0 to 6 months.

Results

Compared with a smoothed SIR of ≤1, smoothed SIRs from 1 to 3, from 3 to 4, and greater than 4 for COVID-19 hospital admissions were associated with a subsequent increase in hospital admissions for self-harm, with a time lag of 2 to 4 months, 4 months, and 6 months, respectively.

Conclusions

A high SIR for hospital admissions for COVID-19 was a risk factor for hospital admission for self-harm some months after the epidemic peaks. This finding emphasizes the importance of monitoring and seeking to prevent suicide attempts outside the epidemic peak periods.

Objective and subjective neighbourhood characteristics and suicidality: a multilevel analysis

BACKGROUND

Characteristics of the neighbourhood environment, including population density, social fragmentation, and trust, have been linked to mental health outcomes. Using a longitudinal population-based cohort, we explored the relationship between objective and subjective neighbourhood characteristics and the odds of suicidal thoughts and attempts.

METHODS

We conducted a longitudinal study of 20764 participants living in Stockholm County who participated in the Stockholm Public Health Survey. We used multilevel modelling to examine if suicidal thoughts and attempts were associated with neighbourhood characteristics, independent of individual associations. We included objective and subjective measures to explore if there was a different relationship between these measures of the neighbourhood environment and suicidality.

RESULTS

Associations between neighbourhood factors and suicidality were predominantly explained by individual characteristics, with the exception of neighbourhood-level deprivation and average residential trust. Each unit increase of deprivation was linked to increased odds of suicidal thoughts [Odds ratio (OR) 1.04, 95% confidence interval (CI) 1.00-1.07] and attempts (OR 1.11, 95% CI 1.06-1.17). Decreasing residential trust was associated with increased odds of suicide attempts (OR 1.09, 95% CI 1.02-1.17). There was no evidence that neighbourhood-level fragmentation or average trust in public and political institutions had an independent effect on suicidality once individual and sociodemographic factors were accounted for.

CONCLUSIONS

This study showed that much of the neighbourhood-level variation in suicidal thoughts and attempts could be explained by compositional factors, including sociodemographic clustering within neighbourhoods. The independent effect of neighbourhood-level deprivation and average residential trust provide evidence that the neighbourhood context may exert an independent effect on suicidality beyond the impact of individual characteristics.

Neighborhood social context and suicide mortality: A multilevel register-based 5-year follow-up study of 2.7 million individuals

Previous studies have linked neighborhood social characteristics to suicide mortality. However, the effects of the operational definition of neighborhoods and the general importance of neighborhood context on suicide mortality have received little attention, with most studies using various administrative areas as neighborhood delineations. In this study, neighborhoods were delineated by micro-areas generated with an automated redistricting algorithm and divided by physical barriers, such as large roads. The geographic data were linked to register data on the Danish adult population in the age range of 20-59 years in December 2013 (N = 2,672,799 individuals nested into 7943 neighborhoods). This cohort was followed for five years to evaluate the association between suicide mortality and neighborhood socioeconomic deprivation, social fragmentation, and population density. We used the median hazard ratio (MHR) to quantify the general contextual effect (GCE) of neighborhoods on suicide mortality and hazard ratios to quantify the specific contextual effects (SCEs) using multilevel survival models stratified by age group. The results showed a larger GCE and larger SCEs of neighborhoods on suicide mortality for individuals aged 20-39 years compared with those aged 40-59 years. After controlling for individual characteristics, higher suicide mortality was observed for individuals living in the least densely populated neighborhoods and the most socially fragmented neighborhoods for both age groups. We found cross-level interactions between neighborhood population density and gender and ethnicity for those aged 40-59 years, as well as between neighborhood social fragmentation and ethnicity for those aged 20-39 years. The results indicate that beyond individual characteristics, the neighborhood social context may affect the risk of suicide, especially for people aged 20-39 years.

Association between Suicide Rate and Human Development Index, Income, and the Political System in 46 Muslim-Majority Countries: An Ecological Study

Very little has been researched assessing the relationship between the suicide rate and the ecological perspectives of the country, especially in the Muslim majority countries. We aimed to determine the association between suicide rate and the ecological parameters of 46 Muslim majority countries. We extracted the Muslim majority countries and their suicide rate, income distribution, distribution of the WHO region and continents, and Human Development Index (HDI). We assessed the correlation of the proportion of Muslim populations, the total population of the countries, number of suicides, continent, income group, political system, and HDI score with the suicide rate. The median suicide rate was 5.45 (IQR = 4.8); 2.9 (IQR = 4) in females and 7.45 (IQR = 8.2) in males per 100,000 population. The males had a significantly higher rate and the highest suicide rate was found in Africa. There are inverse associations between the total suicide rate, the rate in males, and females with HDI, and the income of the country. Furthermore, the suicide rate was significantly higher in countries with democratic systems compared to non-democratic countries. The findings suggest that ecological parameters may have an etiological role on suicides in Muslim countries where HDI and income are inversely associated with suicide rates.

Suicide rates across income levels: Retrospective cohort data on 1 million participants collected between 2003 and 2013 in South Korea

Background

The relation of income and socioeconomic status with suicide rates remains unclear. Most previous studies have focused on the relationship between suicide rates and macroeconomic factors (e.g., economic growth rate). Therefore, we aimed to identify the relationship between individuals' socioeconomic position and suicide risk.

Methods

We analyzed suicide mortality rates across socioeconomic positions to identify potential trends using observational data on suicide mortality collected between January 2003 and December 2013 from 1,025,340 national health insurance enrollees. We followed the subjects for 123.5 months on average. Socioeconomic position was estimated using insurance premium levels. To examine the hazard ratios of suicide mortality in various socioeconomic positions, we used Cox proportional hazard models.

Results

We found that the hazard ratios of suicide showed an increasing trend as socioeconomic position decreased. After adjusting for gender, age, geographic location, and disability level, Medicaid recipients had the highest suicide hazard ratio (2.28; 95% CI, 1.87–2.77). Among the Medicaid recipients, men had higher hazard ratios than women (2.79; 95% CI, 2.17–3.59 vs. 1.71; 95% CI, 1.25–2.34). Hazard ratios also varied across age groups. The highest hazard ratio was found in the 40–59-year-old group (3.19; 95% CI, 2.31–4.43), whereas the lowest ratio was found in those 60 years and older (1.44; 95% CI, 1.09–1.87).

Conclusions

Our results illuminate the relationship between socioeconomic position and suicide rates and can be used to design and implement future policies on suicide prevention.

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Suicide showed an increasing trend as income levels decreased.

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Suicide was most frequent in Medicaid recipients.

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Suicide showed different trends across gender and age groups.

Suicide rate in relation to the Human Development Index and other health related factors: A global ecological study from 91 countries

There has been no worldwide ecological study on suicide as a global major public health problem. This study aimed to identify the variations in suicide specific rates using the Human Development Index (HDI) and some health related variables among countries around the world. In this ecological study, we obtained the data from the World Bank Report 2013. The analysis was restricted to 91 countries for which both the epidemiologic data from the suicide rates and HDI were available. Overall, the global prevalence of suicide rate was 10.5 (95% confidence intervals: 8.8, 12.2) per 100,000 individuals, which significantly varied according to gender (16.3 in males vs. 4.6 in females, p < 0.001) and different levels of human development (11.64/100,000 individuals in very high development countries, 7.93/100,000 individuals in medium development countries, and 13.94/100,000 individuals in high development countries, p = 0.004). In conclusion, the suicide rate varies greatly between countries with different development levels. Our findings also suggest that male gender and HDI components are associated with an increased risk of suicide behaviors. Hence, detecting population subgroups with a high suicide risk and reducing the inequality of socioeconomic determinants are necessary to prevent this disorder around the world.

The area level association between suicide, deprivation, social fragmentation and population density in the Republic of Ireland: a national study

PURPOSE

Numerous studies have examined the ecological relationship between suicide and area level determinants such as deprivation and social fragmentation. In Ireland, there is considerable geographic variation in the rates of suicide. However, there is a dearth of Irish studies investigating the geographic variability of suicide.

METHODS

The Irish Central Statistics Office (CSO) provided data relating to all deaths by suicide and deaths of undetermined intent that occurred from 2009 to 2011. Negative binomial regression was used to examine the relationship between area level suicide rates and measures of deprivation, social fragmentation and population density that were taken from the 2011 National Census.

RESULTS

Overall deprivation had the strongest independent effect on small-area rates of suicide, with the most deprived areas showing the greatest risk of suicide (risk ratio = 2.1; 95 % CI 1.70-2.52). Low population density (rurality) was associated with an increased risk suicide in males across both age groups and among females in the older 40-64-year age group. Conversely, a weak association between high population density (urbanicity) and increased suicide risk was found among females in the 15-39-year age group. Associations with social fragmentation only became apparent in the sub group analysis. Social fragmentation was associated with an elevated risk of suicide in the older 40-64 age group, with this effect being most pronounced among females.

CONCLUSION

The findings of this study demonstrate marked geographical inequalities in the distribution of suicide in Ireland and highlight the importance of targeting suicide prevention resources in the most deprived areas.

GIS-based Association Between PM10 and Allergic Diseases in Seoul: Implications for Health and Environmental Policy

Purpose

The role of PM10 in the development of allergic diseases remains controversial among epidemiological studies, partly due to the inability to control for spatial variations in large-scale risk factors. This study aims to investigate spatial correspondence between the level of PM10 and allergic diseases at the sub-district level in Seoul, Korea, in order to evaluate whether the impact of PM10 is observable and spatially varies across the subdistricts.

Methods

PM10 measurements at 25 monitoring stations in the city were interpolated to 424 sub-districts where annual inpatient and outpatient count data for 3 types of allergic diseases (atopic dermatitis, asthma, and allergic rhinitis) were collected. We estimated multiple ordinary least square regression models to examine the association of the PM10 level with each of the allergic diseases, controlling for various sub-district level covariates. Geographically weighted regression (GWR) models were conducted to evaluate how the impact of PM10 varies across the sub-districts.

Results

PM10 was found to be a significant predictor of atopic dermatitis patient count (P<0.01), with greater association when spatially interpolated at the sub-district level. No significant effect of PM10 was observed on allergic rhinitis and asthma when socioeconomic factors were controlled for. GWR models revealed spatial variation of PM10 effects on atopic dermatitis across the sub-districts in Seoul. The relationship of PM10 levels to atopic dermatitis patient counts is found to be significant only in the Gangbuk region (P<0.01), along with other covariates including average land value, poverty rate, level of education and apartment rate (P<0.01).

Conclusions

Our findings imply that PM10 effects on allergic diseases might not be consistent throughout Seoul. GIS-based spatial modeling techniques could play a role in evaluating spatial variation of air pollution impacts on allergic diseases at the sub-district level, which could provide valuable guidelines for environmental and public health policymakers.

"Geography of suicide in Hong Kong: spatial patterning, and socioeconomic correlates and inequalities"

Past urban research on Western nations tends to show high suicide rates in inner city and socioeconomically deprived areas. However, little is known about geographic variations in suicide in non-Western cities. We used Bayesian hierarchical models to estimate smoothed standardised mortality ratios (2005-2010) for suicide in people aged 10 years or above in each geographic unit in Hong Kong at two levels, i.e. large street block (n = 1639; median population = 1860) and small tertiary planning unit group (n = 204; median population = 14,850). We further analysed their associations with a range of area socioeconomic characteristics and a deprivation index. The "city centre" of Hong Kong, a generally non-deprived area, showed mostly below average suicide rates. However, there were high rates concentrating in some socioeconomically deprived, densely populated areas, including some inner city areas, across the city. Males had greater geographic variations in rates than females, except the elderly group. The use of smaller geographic units revealed finer detailed suicide distribution than the use of larger units, and showed that suicide rates were associated with indicators of socioeconomic deprivation (population with non-professional jobs and low median household income), and social fragmentation (proportions of unmarried adults and divorced/separated adults), but not with Gini coefficient. Sex/age groups had different associations with suicide rates. Areas in the most deprived quintile had a suicide rate more than two times higher than the least deprived. The association between suicide and deprivation was stronger in males than females and more marked in the younger populations compared to the elderly. The spatial distribution of suicide in Hong Kong showed distinct patterning and a stronger association with income compared to findings from Western countries. Suicide prevention strategies should consider tackling the marked socioeconomic gradient in suicide and high risk in young and middle-aged males living in deprived areas.

Overall, gender and social inequalities in suicide mortality in Iran, 2006-2010: a time trend province-level study

OBJECTIVES

Suicide is a major global health problem imposing a considerable burden on populations in terms of disability-adjusted life years. There has been an increasing trend in fatal and attempted suicide in Iran over the past few decades. The aim of the current study was to assess overall, gender and social inequalities across Iran's provinces during 2006-2010.

DESIGN

Ecological study.

SETTING

The data on distribution of population at the provinces were obtained from the Statistical Centre of Iran. The data on the annual number of deaths caused by suicide in each province were gathered from the Iranian Forensic Medicine Organization.

METHODS

Suicide mortality rate per 100,000 population was calculated. Human Development Index was used as the provinces' social rank. Gini coefficient, rate ratio and Kunst and Mackenbach relative index of inequality were used to assess overall, gender and social inequalities, respectively. Annual percentage change was calculated using Joinpoint regression.

RESULTS

Suicide mortality has slightly increased in Iran during 2006-2010. There was a substantial and constant overall inequality across the country over the study period. Male-to-female rate ratio was 2.34 (95% CI 1.45 to 3.79) over the same period. There were social inequalities in suicide mortality in favour of people in better-off provinces. In addition, there was an increasing trend in these social disparities over time, although it was not statistically significant.

CONCLUSIONS

We found substantial overall, gender and social disparities in the distribution of suicide mortality across the provinces in Iran. The findings showed that men in the provinces with low socioeconomic status are at higher risk of suicide mortality. Further analyses are needed to explain these disparities.

An ecological study on suicide and homicide in Brazil

The objective was to evaluate correlations between suicide, homicide and socio-demographic variables by an ecological study. Mortality and socio-demographic data were collected from official records of the Ministry of Health and IBGE (2010), aggregated by state (27). The data were analyzed using correlation techniques, factor analysis, principal component analysis with a varimax rotation and multiple linear regression. Suicide age-adjusted rates for the total population, men and women were 5.0, 8.0, and 2.2 per 100,000 inhabitants respectively. The suicide rates ranged from 2.7 in Pará to 9.1 in Rio Grande do Sul. Homicide for the total population, men and women were 27.2, 50.8, and 4.5 per 100,000, respectively. The homicide rates ranged from 13.0 in Santa Catarina to 68.9 in Alagoas. Suicide and homicide were negatively associated, the significance persisted among men. Unemployment was negatively correlated with suicide and positively with homicide. Different socio-demographic variables were found to correlate with suicide and homicide in the regressions. Suicide showed a pattern suggesting that, in Brazil, it is related to high socioeconomic status. Homicide seemed to follow the pattern found in other countries, associated with lower social and economic status.

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.

Spatial clusters of suicide in the municipality of São Paulo 1996-2005: an ecological study

BACKGROUND

In a classical study, Durkheim mapped suicide rates, wealth, and low family density and realized that they clustered in northern France. Assessing others variables, such as religious society, he constructed a framework for the analysis of the suicide, which still allows international comparisons using the same basic methodology. The present study aims to identify possible significantly clusters of suicide in the city of São Paulo, and then, verify their statistical associations with socio-economic and cultural characteristics.

METHODS

A spatial scan statistical test was performed to analyze the geographical pattern of suicide deaths of residents in the city of São Paulo by Administrative District, from 1996 to 2005. Relative risks and high and/or low clusters were calculated accounting for gender and age as co-variates, were analyzed using spatial scan statistics to identify geographical patterns. Logistic regression was used to estimate associations with socioeconomic variables, considering, the spatial cluster of high suicide rates as the response variable. Drawing from Durkheim's original work, current World Health Organization (WHO) reports and recent reviews, the following independent variables were considered: marital status, income, education, religion, and migration.

RESULTS

The mean suicide rate was 4.1/100,000 inhabitant-years. Against this baseline, two clusters were identified: the first, of increased risk (RR=1.66), comprising 18 districts in the central region; the second, of decreased risk (RR=0.78), including 14 districts in the southern region. The downtown area toward the southwestern region of the city displayed the highest risk for suicide, and though the overall risk may be considered low, the rate climbs up to an intermediate level in this region. One logistic regression analysis contrasted the risk cluster (18 districts) against the other remaining 78 districts, testing the effects of socioeconomic-cultural variables. The following categories of proportion of persons within the clusters were identified as risk factors: singles (OR=2.36), migrants (OR=1.50), Catholics (OR=1.37) and higher income (OR=1.06). In a second logistic model, likewise conceived, the following categories of proportion of persons were identified as protective factors: married (OR=0.49) and Evangelical (OR=0.60).

CONCLUSIONS

This risk/ protection profile is in accordance with the interpretation that, as a social phenomenon, suicide is related to social isolation. Thus, the classical framework put forward by Durkheim seems to still hold, even though its categorical expression requires re-interpretation.

Suicide rate differences by sex, age, and urbanicity, and related regional factors in Korea

Objectives

Identify the characteristics related to the suicide rates in rural and urban areas of Korea and discover the factors that influence the suicide rate of the rural and urban areas.

Methods

Using the data on causes of death from 2006 to 2008, the suicide rates were calculated and compared after age-standardization based on gender, age group and urbanicity. And, in order to understand the factors that influence suicide rate, total 10 local characteristics in four domains - public service, social integration, residential environment, and economic status - were selected for multiple regression analysis.

Results

The suicide rates were higher in men than women, in rural areas than urban, and in older people than the younger. Generally, although there were variations according to age group and urbanicity, suicide rates were significantly related to residential environment and regional economic status but not related to regional welfare spending and social integration. In addition, the population over the age of 65 years, only regional economic status has significantly influence on their suicide rates.

Conclusions

The influence of characteristics of regions on suicide rate is various by age-group, gender, and urbanicity. Therefore, in order to lower suicide rate and reduce the gap between regions, various approaches must be adopted by taking into account the socioeconomic characteristics of the regions.

Application of commercial software to the classification of suicide cases: a brief report

Mosaic Profiler software was used to classify suicide and open verdict cases during 1996 to 1998 in England and within England, for the London and the North West regions. The classification system was based on the socioeconomic characteristics of the last place of residence of the cases at the level of postcode. The results highlighted that deprived areas and areas that contain elderly population or those areas that suffer from lack of social cohesion are overrepresented, whereas affluent areas are underrepresented. All of these, although in the larger scale, seem to support the results of other studies. Nevertheless, more studies would be required before one can fully evaluate the application of the Mosaic Profiler in the field of spatial epidemiology.

Analyzing the effects of place on injury: Does the choice of geographic scale and zone matter?

BACKGROUND

Recent studies have shown that the morbidity and mortality associated with injury of pedestrians are inversely related to socio-economic status (SES). However, in drawing inferences from this association, investigators have paid little attention to the modifiable artifacts related to scale and how the data are partitioned. The purpose of this population-based study was to identify the relation between SES and incidence patterns of pedestrian injury at 4 different geographic scales.

METHODS

We used a Poisson generalized linear model, stratified by age and sex, to analyze the relation between each of 4 area measures of SES and incidence patterns of pedestrian injuries occurring in metropolitan Vancouver between 1 January 2001 and 31 March 2006. The 4 area measures of SES were based on boundaries of dissemination areas, census tracts, custom-defined census tracts (generated by reassignment of dissemination area boundaries by means of a geographic information system) and census subdivisions of the Canadian census. We measured the SES of the location where the injury occurred with the Vancouver Area Neighbourhood Deprivation Index.

RESULTS

A total of 262 injuries in adults (18 years of age or older) were analyzed. Among adult men, the odds ratio (OR) for injury of pedestrians at the scale of dissemination area was 4.93 (95% confidence interval [CI] 2.89-8.42) for areas having the lowest SES relative to those with the highest SES. For the same population, the OR for injury was lower with increasing aggregation of data: 2.33 (95% CI 1.45-3.74) when census tracts were used, 3.26 (95% CI 2.06-5.16) when modified census tracts were used and 1.27 (95% CI 0.47-3.45) when census subdivisions were used. Among adult women, the OR for pedestrian injury by SES was highest at the scale of census subdivision within medium-low SES areas (4.33, 95% CI 1.23-15.22). At the census subdivision scale, the relation between SES and incidence pattern of injury was not consistent with findings at smaller geographic scales, and the OR for injury decreased with each increase in SES.

INTERPRETATION

In this analysis, there was significant variability when different administrative boundaries were applied as proxy measures of the effects of place on incidence patterns of injury. The hypothesized influence of SES on prevalence of pedestrian injury followed a statistically significant socio-economic gradient when analyzed using small-area boundaries of the census. However, researchers should be aware of the inherent variability that remains even among the more homogenous population units.

e-Infrastructures supporting research into depression, self-harm and suicide

The Economic and Social Research Council (ESRC)-funded Data Management through e-Social Sciences (DAMES) project is investigating, as one of its four research themes, how research into depression, self-harm and suicide may be enhanced through the adoption of e-Science infrastructures and techniques. In this paper, we explore the challenges in supporting such research infrastructures and describe the distributed and heterogeneous datasets that need to be provisioned to support such research. We describe and demonstrate the application of an advanced user and security-driven infrastructure that has been developed specifically to meet these challenges in an on-going study into depression, self-harm and suicide.

GIS and injury prevention and control: history, challenges, and opportunities

Intentional and unintentional injury is the leading cause of death and potential years of life lost in the first four decades of life in industrialized countries around the world. Despite surgical innovations and improved access to emergency care, research has shown that certain populations remain particularly vulnerable to the risks and consequences of injury. Recent evidence has shown that the analytical, data linkage, and mapping tools of geographic information systems (GIS) technology provide can further address these determinants and identify populations in need. This paper traces the history of injury prevention and discusses current and future challenges in furthering our understanding of the determinants of injury through the use of GIS.

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.

Global co-distribution of light at night (LAN) and cancers of prostate, colon, and lung in men

The incidence rates of cancers in men differ by countries of the world. We compared the incidence rates of three of the most common cancers (prostate, lung, and colon) in men residing in 164 different countries with the population-weighted light at night (LAN) exposure and with several developmental and environmental indicators, including per capita income, percent urban population, and electricity consumption. The estimate of per capita LAN exposure was a novel aspect of this study. Both ordinary least squares (OLS) and spatial error (SE) regression models were used in the analysis. We found a significant positive association between population exposure to LAN and incidence rates of prostate cancer, but no such association with lung cancer or colon cancer. The prostate cancer result is consistent with a biological theory and a limited number of previous studies of circadian disruption and risk. The LAN-prostate cancer connection is postulated to be due to suppression of melatonin and/or disruption of clock gene function. An analysis holding other variables at average values across the 164 countries yielded a risk of prostate cancer in the highest LAN-exposed countries 110% higher than in the lowest LAN exposed countries. This observed association is a necessary condition for a potentially large effect of LAN on risk of prostate cancer. However, it is not sufficient due to potential confounding by factors that increase the risk of prostate cancer and are also associated with LAN among the studied countries.

Islam and suicide: a short personal communication

Islamic countries display lower suicide rates compared to the other countries of the world. Since most studies dealing with the relationships between Islam and suicide have focused on the extent of the problem and not the underlying mechanisms, the focus of this brief communication is to provide a rather more in-depth discussion regarding the mechanism of this relation. It also covers issues which may have an adverse effect on suicide within Islamic countries and consequently tries to sketch a path ahead in the area of suicide research within the Islamic countries.

Geographical epidemiology, spatial analysis and geographical information systems: a multidisciplinary glossary

We provide a relatively non-technical glossary of terms and a description of the tools used in spatial or geographical epidemiology and associated geographical information systems. Statistical topics included cover adjustment and standardisation to allow for demographic and other background differences, data structures, data smoothing, spatial autocorrelation and spatial regression. We also discuss the rationale for geographical epidemiology and specific techniques such as disease clustering, disease mapping, ecological analyses, geographical information systems and global positioning systems.