Introduction

Substance use, mental disorders, and arrest are markers of increased firearm injury risk. It is unclear how these markers vary by intent. Examining these interrelated factors together can clarify their associations with assault-related, self-inflicted, unintentional, and legal intervention firearm injuries, informing intent-specific interventions.

Methods

In 2017–2018, 2-year diagnosis and arrest histories of intent-specific firearm injury cases were compared with those of unintentionally injured motor vehicle collision passenger controls. Fatal and nonfatal firearm and motor vehicle collision injury records in Seattle (2010–2014) were linked to statewide hospitalization and arrest records. Multinomial logistic regression models compared odds of prior arrest, substance use, and mental disorder diagnoses among intent-specific firearm injury cases relative to controls, adjusting for age, race, and gender.

Results

A total of 763 cases and 335 controls were identified. Unintentional and self-inflicted cases did not differ significantly from controls in arrest history. Legal intervention cases resembled assault-related cases in their arrest history, and self-inflicted cases in their hospitalization history. The legal intervention cases were more likely than controls to have a prior felony arrest (OR=7.72, 95% CI=2.63, 20.97), and diagnoses involving alcohol (OR=4.06, 95% CI=1.04, 15.84); cannabis (OR=11.00, 95% CI=1.01, 119.36); depression/anxiety (OR=7.22, 95% CI=1.89, 27.67); psychosis (OR=6.99, 95% CI=1.35, 36.24); or conduct disorder (OR=22.01, 95% CI=1.44, 335.93).

Conclusions

Individuals with intent-specific firearm injuries have distinct patterns of prior substance use, mental disorder, and arrest. Many injuries occur after a series of encounters with institutions meant to help individuals during crises that can fail to provide longer-term solutions.