How Do Opioid-Related Suicides and Homicides Compare over Time: Findings from the National Violent Death Reporting System

Background: Current research efforts in substance-use related problems have emphasized the association of opioid use and mortality, including unintentional/intentional overdose and suicide, showing there is an overall increase in these self-harm related events up to the present day. However, there is far less emphasis on how opioid-related problems are associated with other forms of mortality, including opioid-related homicides. In this study, we examine this phenomenon to assess whether the longitudinal trends of violent deaths are similar among opioid-related suicides and opioid-related homicides.

Method: Data is from the National Violent Death Reporting System (NVDRS), which includes all violent deaths from 27 states in the U.S., collected each year from 2003 to 2015. Our sample included all violent deaths that were ruled homicides and suicides (N = 115,503), excluding deaths that were “undetermined” by local Chief Medical Examiners. NVDRS data includes reports from death certificates, as well as coroner, law enforcement, and toxicology reports. To establish opioid-related deaths, ICD-10 cause of death codes associated with opioid use were collapsed to form a binary variable. Additional measures in the NVDRS include race/ethnicity, age, gender, education, marital status, mental health problems, known history of substance use, the experience of interpersonal violence, history of suicide, and whether a firearm was involved in an injury that lead to death. To examine whether there are differences over time in the suicide/homicide rates in opioid-use related deaths, a mixed-effects multivariate logistic regression model examined whether a homicide/suicide by year interaction term was associated with opioid use related deaths, controlling for additional factors associated with violent death.

Results: The multivariate logistic regression model showed that opioid-related deaths were more likely to be classified as suicide (opposed to homicide), to occur among White non-Hispanic individuals (compared to African American individuals), to occur among individuals older in age, individuals who were female, persons with higher education levels, those who were separated/divorced, persons with mental health issues, and persons with substance use problems. Opioid-related deaths were less likely to involve the use of a firearm. Additionally, there was a significant increase in opioid-related deaths among all individuals leading up to the year 2015, and a significant homicide/suicide by year interaction, suggesting that the rate of annual increase for opioid-related homicides was larger compared to opioid-related suicides such that by the year 2015, opioid-related homicides were only slightly lower in rate.

Discussion: While current focus on substance use related deaths concerns overdose and suicide among opioid users, the current study underscores the role that opioids play in other forms of mortality, including homicide. Given the increasing annual trends in opioid-related homicide, social workers, especially those with a focus on addiction, may benefit from this work, by emphasizing through practice the increased risk that opioid-users face across all causes of mortality, including both suicide and homicide. Additionally, social work practitioners of all areas can build on this work to continue advocacy for increased effort to better advocate for resources to address the links between all causes of mortality and opioid use.