Oral anticoagulant use by emergency medical services patients: an observational study

Oral anticoagulant (OAC) use increases the risk of death in conditions like hemorrhagic stroke, trauma, and traumatic brain injury. Early identification of OAC use is critical for timely interventions to mitigate hemorrhage risk and improve survival. We aimed to identify emergency medical services (EMS) care characteristics associated with patients using an OAC.

We analyzed prehospital data (2018-2020) from the ESO Data Collaborative, focusing on adult (≥18 years) 911 EMS calls. The administered OACs were warfarin, dabigatran, rivaroxaban, and apixaban. We compared EMS call characteristics, patient demographics, response times, and interventions between OAC and non-OAC users. We used univariate logistic regression to identify independent predictors of OAC use.

Of 16,244,550 adult 911 EMS events, 906,575 involved OAC users (56 of 1,000 calls). Those using OAC were older (73.6 years vs. 56.9 years) and more often from nursing homes or long-term care facilities (17.0% vs. 9.2%) but less likely to have trauma (14.7% vs. 18.1%) or cardiac arrest (1.2% vs. 1.4%). The most common EMS primary clinical impressions for OAC users were chest pain (7.4%), altered mental status (7.3%), injury (6.5%), abdominal pain (4.3%), and brain injury (2.8%).

OAC users accounted for 1 in 18 adult EMS encounters. Specific patient and call characteristics were associated with OAC use. These findings should be incorporated into EMS training to facilitate recognition and appropriate management of OAC-related emergencies.