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

Objective To estimate the association between homicide and suicide rates in Brazilian municipalities over a period of 7 years.Design We conducted a longitudinal ecological study using annual mortality data from 5507 Brazilian municipalities between 2008 and 2014. Multivariable negative binomial regr...

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Main Authors: Mauricio L Barreto, Daiane Borges Machado, Keltie McDonald, Luis F S Castro-de-Araujo, Flávia Jôse Oliveira Alves
Format: Article
Language:English
Published: BMJ Publishing Group 2020-11-01
Series:BMJ Open
Online Access:https://bmjopen.bmj.com/content/10/11/e040069.full
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spelling doaj-32b13bd13a4049c58c1e48cca7e3677f2021-06-25T12:31:32ZengBMJ Publishing GroupBMJ Open2044-60552020-11-01101110.1136/bmjopen-2020-040069Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalitiesMauricio L Barreto0Daiane Borges Machado1Keltie McDonald2Luis F S Castro-de-Araujo3Flávia Jôse Oliveira Alves41 Public Health Institute, Federal University of Bahia, Salvador, Brazil Center of Data and Knowledge Integration for Health, Salvador, BrazilDivision of Psychiatry, University College London, London, UKCenter of Data and Knowledge Integration for Health, Salvador, BrazilCenter of Data and Knowledge Integration for Health, Salvador, BrazilObjective To estimate the association between homicide and suicide rates in Brazilian municipalities over a period of 7 years.Design We conducted a longitudinal ecological study using annual mortality data from 5507 Brazilian municipalities between 2008 and 2014. Multivariable negative binomial regression models were used to examine the relationship between homicide and suicide rates. Robustness of results was explored using sensitivity analyses to examine the influence of data quality, population size, age and sex on the relationship between homicide and suicide rates.Setting A nationwide study of municipality-level data.Participants Mortality data and corresponding population estimates for municipal populations aged 10 years and older.Primary and secondary outcome measures Age-standardised suicide rates per 100 000.Results Municipal suicide rates were positively associated with municipal homicide rates; after adjusting for socioeconomic and demographic factors, a doubling of the homicide rate was associated with 22% increase in suicide rate (rate ratio=1.22, 95% CI: 1.13 to 1.33). A dose–response effect was observed with 4% increase in suicide rates at the third quintile, 9% at the fourth quintile and 12% at the highest quintile of homicide rates compared with the lowest quintile. The observed effect estimates were robust to sensitivity analyses.Conclusions Municipalities with higher homicide rates have higher suicide rates and the relationship between homicide and suicide rates in Brazil exists independently of many sociodemographic and socioeconomic factors. Our results are in line with the hypothesis that changes in homicide rates lead to changes in suicide rates, although a causal association cannot be established from this study. Suicide and homicide rates have increased in Brazil despite increased community mental health support and incarceration, respectively; therefore, new avenues for intervention are needed. The identification of a positive relationship between homicide and suicide rates suggests that population-based interventions to reduce homicide rates may also reduce suicide rates in Brazil.https://bmjopen.bmj.com/content/10/11/e040069.full
collection DOAJ
language English
format Article
sources DOAJ
author Mauricio L Barreto
Daiane Borges Machado
Keltie McDonald
Luis F S Castro-de-Araujo
Flávia Jôse Oliveira Alves
spellingShingle Mauricio L Barreto
Daiane Borges Machado
Keltie McDonald
Luis F S Castro-de-Araujo
Flávia Jôse Oliveira Alves
Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
BMJ Open
author_facet Mauricio L Barreto
Daiane Borges Machado
Keltie McDonald
Luis F S Castro-de-Araujo
Flávia Jôse Oliveira Alves
author_sort Mauricio L Barreto
title Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
title_short Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
title_full Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
title_fullStr Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
title_full_unstemmed Association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 Brazilian municipalities
title_sort association between homicide rates and suicide rates: a countrywide longitudinal analysis of 5507 brazilian municipalities
publisher BMJ Publishing Group
series BMJ Open
issn 2044-6055
publishDate 2020-11-01
description Objective To estimate the association between homicide and suicide rates in Brazilian municipalities over a period of 7 years.Design We conducted a longitudinal ecological study using annual mortality data from 5507 Brazilian municipalities between 2008 and 2014. Multivariable negative binomial regression models were used to examine the relationship between homicide and suicide rates. Robustness of results was explored using sensitivity analyses to examine the influence of data quality, population size, age and sex on the relationship between homicide and suicide rates.Setting A nationwide study of municipality-level data.Participants Mortality data and corresponding population estimates for municipal populations aged 10 years and older.Primary and secondary outcome measures Age-standardised suicide rates per 100 000.Results Municipal suicide rates were positively associated with municipal homicide rates; after adjusting for socioeconomic and demographic factors, a doubling of the homicide rate was associated with 22% increase in suicide rate (rate ratio=1.22, 95% CI: 1.13 to 1.33). A dose–response effect was observed with 4% increase in suicide rates at the third quintile, 9% at the fourth quintile and 12% at the highest quintile of homicide rates compared with the lowest quintile. The observed effect estimates were robust to sensitivity analyses.Conclusions Municipalities with higher homicide rates have higher suicide rates and the relationship between homicide and suicide rates in Brazil exists independently of many sociodemographic and socioeconomic factors. Our results are in line with the hypothesis that changes in homicide rates lead to changes in suicide rates, although a causal association cannot be established from this study. Suicide and homicide rates have increased in Brazil despite increased community mental health support and incarceration, respectively; therefore, new avenues for intervention are needed. The identification of a positive relationship between homicide and suicide rates suggests that population-based interventions to reduce homicide rates may also reduce suicide rates in Brazil.
url https://bmjopen.bmj.com/content/10/11/e040069.full
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