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Reference: Kemal et al. Emergency department utilization by youth before and after firearm injury. AEM July 2025

Date: July 28, 2025

Guest Skeptic: Dr. Kirsty Challen is a Consultant in Emergency Medicine in the UK and an evidence-based medicine advocate. She’s a seasoned knowledge translator with her wonderful PaperinaPic infographics.  

Case: Your non-US emergency department (ED) has recently been shaken by the attendance of a teenager with a gunshot injury. Subsequent investigation has found he attended a different hospital in the region six weeks ago with a stab wound. The team wonders if that attendance was an opportunity to intervene.

Background: Firearm injuries are now the leading cause of death in youth in the United States, surpassing motor vehicle collisions.[1] While the immediate clinical management of gunshot wounds is well covered in emergency medicine training, there is less clarity around what happens before and after that ED visit. Could we identify these high-risk youth earlier? Do patterns of ED use provide clues for intervention?

The ED often serves as the primary healthcare contact point for youth exposed to community violence. Some youth injured by firearms may have prior ED visits for mental health crises or minor injuries, presenting opportunities for preventative strategies. But are we missing these cues?

Additionally, once youth survive a firearm injury, they face elevated risk for repeat injury, psychological trauma, and even death. Understanding post-injury healthcare utilization may reveal missed chances for intervention, particularly in general EDs that may lack pediatric-specific resources.

Clinical Question: Do youth with firearm injuries have increased emergency department utilization before and after their injury compared to their peers?

Reference: Kemal et al. Emergency department utilization by youth before and after firearm injury. AEM July 2025

  • Population: Youth aged 10 to 19 years who had an index ED visit for a firearm injury in 2019 across eight US states, identified from the Healthcare Cost and Utilization Project database.
    • Exclusion: Youth who lacked the data to assess 90 days before or after the index injury, and those without longitudinal ED visit linkage, injuries from non-power firearms, and recurrent visits with firearm injury.
  • Exposure: Having sustained a firearm injury as indexed by an ED visit.
  • Comparison: ED utilization by the same patients in the 90 days before and after the firearm injury.
  • Outcomes:
    • Primary Outcome: Number and types of ED visits 90 days before and after the index firearm injury.
    • Secondary Outcomes: Types of ED visits and recurrence of trauma.
  • Type of Study: Retrospective cohort study using linked administrative claims data.

Dr. Samaa Kemal

This is an SGEMHOP, and we are pleased to have the lead author on the episode. Dr. Samaa Kemal is an early-career pediatric emergency medicine clinician-investigator at Ann & Robert H. Lurie Children’s Hospital of Chicago. Her work is primarily focused on the intersection of violence and health equity in children. Her research priorities are focused on developing and implementing novel and effective solutions to prevent violent injuries and subsequent adverse outcomes in children. 

Authors’ Conclusions: “Youth have high rates of ED utilization before and after firearm injury. Half of firearm-injured youth receive their emergency care exclusively in general EDs. Implementing firearm injury prevention and intervention efforts in all ED settings is critical.”

Quality Checklist for Observational Study:

  1. Did the study address a clearly focused issue? Yes
  2. Did the authors use an appropriate method to answer their question? Yes
  3. Was the cohort recruited in an acceptable way? Yes
  4. Was the exposure accurately measured to minimize bias? Yes
  5. Was the outcome accurately measured to minimize bias? Yes
  6. Have the authors identified all important confounding factors? No
  7. Was the follow-up of subjects complete enough? Yes
  8. How precise are the results? Fairly precise
  9. Do you believe the results? Yes
  10. Can the results be applied to the local population? No
  11. Do the results of this study fit with other available evidence? Yes
  12. Funding of the Study? Eunice Kennedy Shriver National Institute of Child Health and Human Development

Results: The median age was approximately 17 years; predominantly male and from racially minoritized groups.

Key Result: Youth frequently used EDs before and after injury, suggesting opportunities for early identification and intervention.

  • Primary Outcome: 12.8% of youth had at least one ED visit in the 90 days before the firearm injury, and 22.1% had at least one in the 90 days after.
  • Secondary Outcomes: Of those with post-injury ED visits, 26% had recurrent trauma; mental health and assault-related visits were common.

Listen to the SGEM podcast to hear Samaa answer our five nerdy questions. 

  1. Confounding by Indication and Unmeasured Covariates: One of the primary threats to internal validity in observational studies is confounding. This is especially true when data sources like administrative datasets lack key clinical variables. In this study, firearm-injured youth were not matched to potential confounders such as socioeconomic status, prior trauma history, or mental health diagnoses beyond what was coded. How do you think these unmeasured confounders bias the estimates of associations, because differences in post-injury ED use may reflect underlying vulnerabilities rather than the effect of firearm injury?
  2. Linkage, Follow-up and Dependence on Datasets: You chose these states because you considered that the linkage between ED and inpatient databases was most accurate. Could you talk us through that? How do you assess the accuracy of linkage?
  3. Misclassification of Exposure or Outcome Using Administrative Codes: The reliance on ICD-10 and Clinical Classification Software codes in the Healthcare Cost and Utilization Project (HCUP) databases raises the risk of misclassification bias. Diagnosis codes may be inconsistently applied, and key distinctions such as intentional vs. unintentional firearm injury or severity of psychological outcomes might be missed. Such misclassification is particularly problematic if it differs systematically between groups, which could attenuate or exaggerate true differences in ED utilization. What steps did you take to mitigate against misclassification bias?
  4. Lack of Information on Non-ED Care and Social Determinants of Health: The study’s reliance solely on ED and inpatient data from the HCUP SID and SEDD datasets omits health care utilization in outpatient, urgent care, or community mental health settings. This may underestimate or misrepresent total healthcare use, particularly for youth who might shift to non-ED resources post-trauma. How do you think this gap could bias interpretations about the burden on emergency services, thus threatening external validity when generalizing to broader healthcare utilization patterns?
  5. Temporal Ambiguity and Reverse Causation Risks: Although the study uses a pre-post design anchored on the injury date, temporal ambiguity remains a concern. Reverse causation refers to a scenario where the outcome is not solely a consequence of the exposure, but rather that both the exposure and outcome share a common underlying cause, or that the outcome may have even predatedor influenced the exposure. For example, higher ED utilization post-injury could be attributed not only to the firearm event itself but also to progressive deterioration from unmeasured pre-existing factors. What do you think about the potential for reverse causation?

Comment on the Authors’ Conclusion Compared to the SGEM Conclusion: The authors’ conclusions are supported by the data but should be interpreted with caution. While they call for adapting interventions to all general EDs, this study cannot determine whether such interventions would be effective.

SGEM Bottom Line: Firearm-injured youth frequently present to the ED both before and after injury, representing potential missed opportunities for prevention and follow-up care.

Case Resolution: The second ED visit wasn’t entirely unpredictable. The best predictor of future behaviour is often past behaviour. Recognizing this pattern, your hospital begins piloting a violence intervention program targeting youth with prior ED visits for assault or behavioural concerns. The plan on collect data and see if the intervention has a positive impact.

Dr. Kirsty Challen

Clinical Application: ED providers could use visit history to flag high-risk youth and advocate for violence intervention referrals, social work consults, or follow-up care plans. However, there is a lack of evidence that such interventions would be effective. Further studies are needed to test various interventions, especially in non-pediatric EDs.

What Do I Tell the Patient? You have had a couple of visits to the ED recently. We are worried about you. Are you interested in talking to someone about the violence in your life?

Keener Kontest: The last episode’s winner was David Pecora. He knew that STI we were looking for was Syphilis. The word syphilis comes from the mythic Greek shepherd, Syphilus, who was cursed by the god Apollo with a dread disease

Listen to the SGEM podcast for this week’s question. If you know, then send an email to thesgem@gmail.com with “keener” in the subject line. The first correct answer will receive a shoutout on the next episode.

Now it is your turn, SGEMers. What do you think of this episode on youth firearm injury and ED utilization? What questions do you have for Samaa and their team? Post your comments on social media using #SGEMHOP. The best social media feedback will be published in AEM.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

References:

  1. New Report Highlights U.S. 2022 Gun-Related Deaths: Firearms Remain Leading Cause of Death for Children and Teens, and Disproportionately Affect People of Color https://publichealth.jhu.edu/2024/guns-remain-leading-cause-of-death-for-children-and-teens