Utilization and Metrics Associated with Paramedic Treat and Discharge Medical Directives for Paramedic Services and Emergency Departments: A Retrospective Cohort Study

OBJECTIVES: An emerging strategy to alleviate health care system pressures are prehospital treat and discharge directives, allowing paramedics to manage patient care in the community without transporting to an emergency department (ED). In Ontario, Canada, three discharge directives apply to patients with resolved seizures, resolved hypoglycemia, and resolved supraventricular tachycardia. Our objective was to describe how these directives were utilized in practice and to characterize associated operational metrics and downstream ED utilization among eligible patients. METHODS: We conducted a retrospective cohort study using paramedic records from southwestern Ontario between June 1, 2023, and November 15, 2024. All 9-1-1 calls were screened using objective criteria in the medical directives to identify patients who may have been eligible for paramedic discharge. Patient records were categorized into groups by directive, then classified by their call outcome (transported, discharged by paramedics, patient refusal of transport). Where established linkages existed, transported patient records were linked to their ED visits. We examined paramedic scene times and call durations across groups, and ED metrics of length of stay (LOS), wait time for physician assessment, visit outcome, and visit costs. RESULTS: Of 1,596 patients identified as potentially eligible for discharge, 1,085 (68.0%) were transported to an ED, 474 (29.7%) patients refused transport, and 35 (2.2%) were discharged by paramedics. Paramedic discharged patients had half the median call duration (45 min) of ED transported patients (87 min). Patients with hypoglycemia had a high rate of transport refusal (58.9%), while the cohort of patients with seizure had the highest rate of transport (72.0%). Among 494 patients with linked ED data, the mean ED LOS was 6 h and 20 min. Most were discharged (70.2%) or left before completing care (13.4%). The average ED visit cost was $461 in Canadian dollars (not including physician billing), and the mean wait time for physician assessment exceeded 1.5 h. CONCLUSIONS: Paramedic-initiated discharge was used infrequently, but cases in which it was applied were associated with shorter call durations and avoided subsequent ED utilization. These descriptive findings suggest potential operational advantages worthy of further evaluation, though additional research is needed to determine safety, and system-level impact.