The Role of Interpersonal Conflict as a Determinant of Firearm-Related Homicide–Suicides at Different Ages

Abstract

Although firearm-related homicide-suicides and firearm-related suicides are tragic and catastrophic events, there is increasing evidence that the two events have different precipitants and that understanding these precipitants may help prevention efforts. We aimed to assess the role of interpersonal conflict (IPC) and recent crises in firearm-related homicide-suicides as compared with firearm-related suicides alone. We also assessed whether these differences were consistent across young and old perpetrators. Using an unmatched case-control study, we compared firearm-related homicide-suicides andsuicides alone from 2003 to 2011 in the National Violent Death Registry data to assess the risk associated with IPC and crisis. Survival analysis was performed to compare time-to-incident of homicide-suicide versus suicide only. We derived odds ratios (ORs) and 95% confidence intervals (95%CI) due to IPC and recent crisis from mixed logistic regression models. Stratified analysis by age on the effect of IPC and recent crisis, and type of incident was also performed. After adjusting for relevant covariates, homicide-suicides were more likely than suicide alone following IPC (OR = 20.6, 95%CI = [16.6, 25.7]) and recent crisis (OR = 14.5, 95%CI = [12.4, 16.9]). The risk of firearm homicide-suicide compared with suicide associated with IPC was twice greater among those >30 years compared with those ≤30 years ( p-interaction = .033), and no differential by age associated with recent crisis ( p-interaction = .64). IPC and recent crisis are risk factors for committing homicide-suicides compared with suicides alone, with the risk doubly greater among older than younger perpetrators.