Treatment variability among low-acuity EMS patients in a university hospital ED: a retrospective registry study from...

Emergency medical services (EMS) increasingly convey patients with non-urgent conditions to emergency departments (EDs), contributing to pressure on acute care systems. In many settings, patients classified as low-acuity in the prehospital phase represent a substantial proportion of ED arrivals. This study examined characteristics and ED management patterns among low-acuity EMS conveyances to a university hospital ED in Southwest Finland.

This retrospective registry-based cohort study used linked EMS and hospital data from May 2019 to December 2023. Low-acuity patients were defined as missions with a final urgency category D after on-scene EMS reassessment. In total, 34,898 category D conveyances to the university hospital ED were identified. Multivariable logistic regression analyses focused on the four most common conveyance categories-decrease in common general condition, fall, patient transport, and mental disorder-comprising 21,048 complete-case missions. Outcomes included laboratory testing, imaging, medication administration, and inpatient admission. Associations with age (≥70 vs <70 years), sex, night-time (vs daytime), and weekend (vs weekday) were examined.

Older age was associated with higher odds of diagnostic testing in several conveyance categories. The largest age-related odds ratios were observed in mental disorder conveyances, in which age ≥70 years was associated with higher odds of imaging (odds ratio [OR] 5.00, 95% confidence interval [CI] 3.68; 6.79) and laboratory testing (OR 4.62, 95% CI 3.59; 6.00). Night-time conveyance was associated with lower odds of medication administration across all four conveyance categories and with lower odds of imaging in three categories. In the decrease in common general condition subgroup, night-time conveyance was associated with lower odds of laboratory testing (OR 0.41, 95% CI 0.30; 0.56). In the patient transport subgroup, night-time conveyance was associated with higher odds of inpatient admission (OR 1.49, 95% CI 1.27; 1.74). Associations with sex and weekend conveyance varied across categories.

ED management of low-acuity EMS patients varies by age, sex, time of conveyance, and conveyance category. These findings suggest that downstream hospital care for low-acuity EMS patients is shaped not only by patient characteristics but also by temporal and organizational factors. Linked prehospital and hospital registry data can provide system-level evidence to support the development of more appropriate acute care pathways.