Oral Anticoagulant Use by Emergency Medical Services Patients in the United States

ABSTRACT OBJECTIVE Oral anticoagulant (OAC) use raises the risk of death in life-threatening conditions such as hemorrhagic stroke, trauma and traumatic brain injury. We sought to describe the national characteristics of Emergency Medical Services patients with a history of OAC use. METHODS We used prehospital electronic medical record data from 2018-2020 from the ESO Data Collaborative. We included adults (age≥18 years) receiving 911 EMS care. OAC use included warfarin, dabigatran, rivaroxaban and apixaban. We determined the incidence of EMS calls by OAC users as well as their variation by EMS agency. We compared EMS call, patient, and response characteristics between OAC and non-OAC users, including primary impressions and hospital diagnoses. RESULTS There were 16,244,550 adult 911 EMS events, including 906,575 by OAC users (56 per 1,000 911 events). Compared with non-OAC users, OAC users were more likely to be older (73.6 vs. 56.9 years), white (78.0% vs. 51.4%) and non-Hispanic (84.5% vs. 78.0%). Incidents involving OAC users were more likely at nursing homes, rehabilitation or long-term care facilities (17.0% vs. 9.2%) but less likely to involve trauma (14.7% vs. 18.1%) or cardiac arrest (1.2% vs. 1.4%). Among OAC users, the most common EMS primary clinical impressions were chest pain (7.4%), altered mental status (7.3%), injury (6.5%), abdominal pain (4.3%), and brain injury (2.8%). CONCLUSIONS In this national series of prehospital events, 1 in 18 adult EMS encounters involved OAC users. These results provide key perspectives on the presentation of the OAC users in EMS care.