Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities

One stream, two channels? A parallel-process latent class growth model of homicide rates and suicide rates in 183 countries, between 2000 and 2019

Background

Suicide and homicide have long been viewed in Western culture as moral, ethical and legal equivalents. This view has underpinned many theoretical and empirical explorations into their relationship over the centuries. However, there has been little evaluation of longitudinal heterogeneity.

Methods

Suicide and homicide rates in 183 countries between 2000 and 2019 were collected from the World Health Organization Global Health Observatory Repository. Corresponding structural variables (i.e., GDP per capita, unemployment rate, percentage of urban population, percentage of elderly population, and Gini index) were acquired from The World Bank and Standardized World Income Inequality Database. Parallel-process latent class growth modelling was applied to identify different classes within the joint suicide and homicide rate trajectories. Multinomial logistic regression examined relationships between the structural covariates and trajectory classes.

Results

Four trajectory classes were identified, two with inverse relationships between suicide and homicide, and two with parallel relationships: 1) countries with increasing suicide rates and decreasing homicide rates ("suicide up, homicide down": UD, n = 41) or 2) countries with decreasing suicide rates and increasing homicide rates ("suicide down, homicide up": DU, n = 17); and 3) countries where suicide and homicide rates both trended up (UU, n = 19), or 4) both trended down (DD, n = 106). A higher average annual growth rate (AAGR) of GDP per capita was related to an increased possibility of being in DD than in DU. Countries with higher AAGR in unemployment rates were more likely to be in UD and UU than in DD, while those with higher AAGR in urbanization were less likely to be in UD than in DD.

Conclusion

The over-time relationship between suicide and homicide is heterogenous and complex. It is influenced differently by GDP per capita, urbanization and unemployment in different countries, and it is not well described by a single theory.

Contextual factors associated with country-level suicide mortality in the Americas, 2000-2019: a cross-sectional ecological study

Background

The suicide mortality rate in the Region of the Americas has been increasing, while decreasing in all other World Health Organization regions; highlighting the urgent need for enhanced prevention efforts. Gaining a better understanding of population-level contextual factors associated with suicide may aid such efforts. We aimed to evaluate the contextual factors associated with country-level, sex-specific suicide mortality rates in the Region of the Americas for 2000-2019.

Methods

Annual sex-specific age-standardized suicide mortality estimates were obtained from the World Health Organization (WHO) Global Health Estimates database. To investigate the sex-specific suicide mortality rate trend over time in the region, we performed joinpoint regression analysis. We then applied a linear mixed model to estimate the effects of specific contextual factors on the suicide mortality rate across countries in the region over time. All potentially relevant contextual factors, obtained from the Global Burden of Disease Study 2019 covariates and The World Bank, were selected in a step-wise manner.

Findings

We found that the mean country-level suicide mortality rate among males in the region decreased as health expenditure per capita and the proportion of the country with a moderate population density increased; and increased as the death rate due to homicide, prevalence of intravenous drug use, risk-weighted prevalence of alcohol use, and unemployment rate increased. The mean country-level suicide mortality rate among females in the region decreased as the number of employed medical doctors per 10,000 population and the proportion of the country with a moderate population density increased; and increased when relative education inequality and unemployment rate increased.

Interpretation

Although there was some overlap, the contextual factors that significantly impacted the suicide mortality rate among males and females were largely different, which mirrors the current literature on individual-level risk factors for suicide. Taken together, our data supports that sex should be considered when adapting and testing suicide risk reduction interventions, and when developing national suicide prevention strategies.

Funding

This work received no funding.

Relationship between the Bolsa Família national cash transfer programme and suicide incidence in Brazil: A quasi-experimental study

BACKGROUND

Socioeconomic factors have been consistently associated with suicide, and economic recessions are linked to rising suicide rates. However, evidence on the impact of socioeconomic interventions to reduce suicide rates is limited. This study investigates the association of the world's largest conditional cash transfer programme with suicide rates in a cohort of half of the Brazilian population.

METHODS AND FINDINGS

We used data from the 100 Million Brazilian Cohort, covering a 12-year period (2004 to 2015). It comprises socioeconomic and demographic information on 114,008,317 individuals, linked to the "Bolsa Família" programme (BFP) payroll database, and nationwide death registration data. BFP was implemented by the Brazilian government in 2004. We estimated the association of BFP using inverse probability of treatment weighting, estimating the weights for BFP beneficiaries (weight = 1) and nonbeneficiaries by the inverse probability of receiving treatment (weight = E(ps)/(1-E(ps))). We used an average treatment effect on the treated (ATT) estimator and fitted Poisson models to estimate the incidence rate ratios (IRRs) for suicide associated with BFP experience. At the cohort baseline, BFP beneficiaries were younger (median age 27.4 versus 35.4), had higher unemployment rates (56% versus 32%), a lower level of education, resided in rural areas, and experienced worse household conditions. There were 36,742 suicide cases among the 76,532,158 individuals aged 10 years, or older, followed for 489,500,000 person-years at risk. Suicide rates among beneficiaries and nonbeneficiaries were 5.4 (95% CI = 5.32, 5.47, p < 0.001) and 10.7 (95% CI = 10.51, 10.87, p < 0.001) per 100,000 individuals, respectively. BFP beneficiaries had a lower suicide rate than nonbeneficiaries (IRR = 0.44, 95% CI = 0.42, 0.45, p < 0.001). This association was stronger among women (IRR = 0.36, 95% CI = 0.33, 0.38, p < 0.001), and individuals aged between 25 and 59 (IRR = 0.41, 95% CI = 0.40, 0.43, p < 0.001). Study limitations include a lack of control for previous mental disorders and access to means of suicide, and the possible under-registration of suicide cases due to stigma.

CONCLUSIONS

We observed that BFP was associated with lower suicide rates, with similar results in all sensitivity analyses. These findings should help to inform policymakers and health authorities to better design suicide prevention strategies. Targeting social determinants using cash transfer programmes could be important in limiting suicide, which is predicted to rise with the economic recession, consequent to the Coronavirus Disease 2019 (COVID-19) pandemic.

Interpersonal violence and depression in Brazil: A cross-sectional analysis of the 2019 National Health Survey

Depression and interpersonal violence are issues of increasing public health concern globally, especially in low-and-middle income countries. Despite the known relationship between interpersonal violence and an increased risk of depression, there is a need to further characterise the experience of depression in those who have experienced violence, to better develop screening and treatment interventions. A cross-sectional analysis was conducted on responses from the 2019 Brazilian National Health Survey. The prevalence of depression (both clinician-diagnosed, and Patient Health Questionnaire (PHQ-9) screened) were estimated by type of violence experienced in the preceding 12 months (none, physical violence, sexual violence, physical and sexual violence, or threat of violence). Logistic regression models assessed the associations between violence and depression after adjusting for socioeconomic and demographic factors. Of 88,531 respondents, 8.1% experienced any type of violence. Compared to those not experiencing violence, those who experienced any type of violence had a higher prevalence of clinician-diagnosed or PHQ-9-screened depression (e.g. the prevalence of clinician-diagnosed depression was 18.8% for those experiencing sexual violence compared to 9.5% for those not experiencing violence). Both undiagnosed and untreated depression were also more prevalent in those experiencing any type of violence. In logistic regression models, any experience of violence was associated with a higher odds of depression (e.g. aOR = 3.75 (95% CI: 3.06-4.59) for PHQ-9-detected depression). Experiencing violence was also associated with a higher likelihood of having depression which was undiagnosed (e.g. in those who experienced sexual violence: aOR of 3.20, 95% CI 1.81-5.67) or untreated (e.g. in those who experienced physical and sexual violence: aOR = 8.06, 95% CI 3.44-18.9). These findings highlight the need to consider screening for depression in those affected by violence, and to prioritise mental healthcare in communities affected by violence.

Cross-national examination of adolescent suicidal behavior: a pooled and multi-level analysis of 193,484 students from 53 LMIC countries

INTRODUCTION

Suicide is a leading cause of adolescent mortality worldwide. We aimed to estimate the prevalence and identify individual-level and country-level factors which might explain the variability in suicidal behavior among students in 53 low to middle income countries.

METHODS

We used data on adolescents aged 12-16 years from the Global School-based Student Health Surveys from 2009-2016. The suicidal behaviors investigated included suicide ideation, suicidal planning and suicide attempt. The prevalence was estimated for 53 countries, while a multilevel logistic regression analysis (33 countries) was used to investigate the associations of these behaviors with individual and country-level contextual risk factors. The contextual variables included the Gini Coefficient, Gross Domestic Product per capita, pupil-to-teacher ratios, population density, homicide rates, law criminalizing suicide and the night light index.

RESULTS

The overall prevalence of suicide ideation, making a plan and suicide attempt were 10.4%, 10.3% and 11.0%, respectively. The highest prevalence rates reported were from the Americas. The strongest risk factors associated with suicidal behavior included anxiety, loneliness, no close friends and the substance abuse. Among the country level variables, the night light index was associated with making a suicide plan and attempting suicide.

CONCLUSION

The non-significant country level findings were not entirely surprising given the mixed results from prior studies. Additional knowledge is thus achieved with regard to country level factors associated with suicidal behavior across adolescent populations.