Machado Daiane Borges, McDonald Keltie, Castro-de-Araujo Luis F S, Devakumar Delan, Alves Flávia Jôse Oliveira, Kiss Lígia, Lewis Glyn, Barreto Mauricio L
Center of Data and Knowledge Integration for Health, Salvador, Brazil.
Centre for Global Mental Health, London School of Hygiene & Tropical Medicine, London, United Kingdom.
BMJ Open. 2020 Nov 4;10(11):e040069. doi: 10.1136/bmjopen-2020-040069.
To estimate the association between homicide and suicide rates in Brazilian municipalities over a period of 7 years.
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.
A nationwide study of municipality-level data.
Mortality data and corresponding population estimates for municipal populations aged 10 years and older.
Age-standardised suicide rates per 100 000.
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.
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.
评估巴西各市镇7年间杀人率与自杀率之间的关联。
我们利用2008年至2014年期间5507个巴西市镇的年度死亡率数据进行了一项纵向生态学研究。采用多变量负二项回归模型来检验杀人率与自杀率之间的关系。通过敏感性分析来探讨结果的稳健性，以检验数据质量、人口规模、年龄和性别对杀人率与自杀率之间关系的影响。
一项针对市镇层面数据的全国性研究。
10岁及以上市镇人口的死亡率数据及相应的人口估计数。
每10万人的年龄标准化自杀率。
市镇自杀率与市镇杀人率呈正相关；在调整社会经济和人口因素后，杀人率翻倍与自杀率增加22%相关（率比=1.22，95%置信区间：1.13至1.33）。观察到剂量反应效应，与最低五分位数相比，杀人率第三五分位数时自杀率增加4%，第四五分位数时增加9%，最高五分位数时增加12%。观察到的效应估计值对敏感性分析具有稳健性。
杀人率较高的市镇自杀率也较高，巴西杀人率与自杀率之间的关系独立于许多社会人口和社会经济因素而存在。我们的结果符合杀人率变化导致自杀率变化这一假设，尽管本研究无法确立因果关联。尽管社区心理健康支持和监禁分别有所增加，但巴西的自杀率和杀人率仍有所上升；因此，需要新的干预途径。杀人率与自杀率之间呈正相关表明，在巴西基于人群的降低杀人率干预措施也可能降低自杀率。
