Background
Emergency medical services (EMS) play a pivotal role in the initial management of trauma patients, where timely and effective interventions can significantly influence outcomes. Despite advances in trauma care, the association between the volume of trauma cases managed by individual EMS clinicians and patient mortality remains underexplored. This study addresses this gap by examining how clinician experience, measured by annual trauma patient volume, impacts early mortality rates.
Study Design
The study is a secondary subset analysis of the Linking Investigations in Trauma and Emergency Services (LITES) Task Order 1 study, a prospective observational cohort conducted from 2017 to 2021. It included severely injured patients (Injury Severity Score ≥9) transported to trauma centers by one air and one ground EMS agency. Data from 6769 patient-clinician interactions involving 359 clinicians and 3649 patients were analyzed. The primary exposure was the EMS crew’s mean 3-year adult trauma volume, with outcomes including 6-hour mortality, in-hospital mortality, and EMS quality metrics like scene time and intubation success.
Key Findings
The study revealed a 10% decrease in 6-hour mortality (adjusted odds ratio [aOR], 0.899; 95% CI, 0.811-0.996) and a 2.6% decrease in in-hospital mortality (aOR, 0.974; 95% CI, 0.949-0.999) for every increase of 5 adult trauma patients annually per crew. Subgroup analyses confirmed these associations in traumatic brain injury and prehospital shock patients. Notably, scene time decreased significantly with higher clinician volume (regression coefficient, -0.134; 95% CI, -0.191 to -0.077), and intubation procedural volume was linked to higher success rates without complications (aOR, 1.110; 95% CI, 1.040-1.190).
Expert Commentary
These findings underscore the importance of clinician experience in trauma care, suggesting that higher exposure to trauma cases enhances procedural proficiency and decision-making under pressure. However, the study’s observational nature limits causal inferences, and further research is needed to optimize EMS staffing and training protocols.
Conclusion
This study provides compelling evidence that higher trauma patient volumes per EMS clinician are associated with improved early survival outcomes. These insights could inform policy decisions on EMS workforce planning and education, ultimately enhancing trauma care delivery.

