Associations between nonfatal firearm injuries and risk of subsequent suicide among Veteran VA users: A retrospective cohort study

Background: Suicide is a leading cause of death in the United States, particularly among Veterans. Nonfatal firearm injuries may indicate subsequent risk of suicide and, thus, provide important opportunities for prevention in emergency departments and other health care settings. We used a retrospective cohort design to analyze associations between nonfatal firearm injuries and subsequent suicide among all Veterans who used U.S. Department of Veterans Affairs (VA) health care, nationally, between 2010 and 2019. Methods: We linked VA health care and mortality data to identify VA users, nonfatal firearm injuries, and deaths. International Classification of Diseases (ICD)–10th Revision cause-of-death codes were used to identify suicides. Veterans' firearm injuries and their intent were categorized using cause-of-injury codes from the ICD Clinical Modification–9th and 10th Revisions systems. Using bivariable and multivariable regression, we estimated risk of subsequent suicide among Veterans with, versus without, nonfatal firearm injuries. Among Veterans with nonfatal firearm injuries, we examined characteristics associated with subsequent suicide; electronic health record (chart) reviews explored documentation about firearm access among those who died. Results: Among 9,817,020 VA-using Veterans, 11,503 experienced nonfatal firearm injuries (64.9% unintentional, 12.3% intentional self-harm, 18.5% assault). Of these, 69 (0.6%) subsequently died by suicide (42 involving firearms). The odds of subsequent suicide among Veterans with, versus without, nonfatal firearm injuries were 2.4 (95% confidence interval 1.9–3.0); odds were only slightly attenuated in multivariable modeling. Among Veterans with nonfatal firearm injuries, those with depression or substance use disorder diagnoses had twice the odds of subsequent suicide than those without. Chart reviews identified small proportions of suicide decedents who were assessed for (21.7%), and/or counseled about (15.9%), firearm access. Conclusions: Findings suggest that Veterans' nonfatal firearm injuries, regardless of injury intent, may be important but underutilized opportunities for suicide prevention. Future work should explore mechanisms to reduce risk among these patients.