Adolescent Nonfatal Firearm Injury Trends at a Level I Trauma Center in King County, WA, 2011-2021

Background: Firearm-related harm is a critical and growing public health problem in the United States, particularly among adolescents. Leveraging multiple data sources can provide a more complete assessment of nonfatal firearm injuries at the local-level, as national-level data may mask variations in firearm injury incidence by and within states. Methods: This retrospective cohort study used data from a Level I Trauma Center in King County, Washington (WA) and the Gun Violence Archive (GVA) to examine adolescent nonfatal firearm injury trends and explore how well trauma registry data are captured in the GVA. We calculated incidence rates per 100,000 population for each year of the study period and by intent, race, age, and sex. Events of gun violence in the GVA were matched to trauma registry data using probabilistic linkage methods. Results: Nonfatal firearm injury incidence rates increased among our sample from 2011 to 2021 (2.65 per 100,000 persons versus 3.38 per 100,000 persons); we observed the highest rate in 2019 (3.71 per 100,000 persons). The majority of nonfatal firearm injuries during the study period were sustained by adolescents who were aged 18-19 (51.8%), Black or African American (56.4%), and male (84.8%). Approximately 42% of trauma registry cases were probabilistically matched to cases in the GVA; assault-related cases, those involving Black adolescents, and those among patients aged 15-17 were captured at a higher proportion in the matched data. Conclusion: The rate of nonfatal firearm injuries among King County adolescents who were captured in the trauma registry increased between 2011 and 2021. These findings indicate the need for local evidence-based policy changes and targeted interventions for adolescents at the highest risk of nonfatal firearm injury in King County, particularly individuals who are Black, male, and aged 18-19.