Prehospital on-site triaging

To estimate the proportion of patients transported by emergency medical services (EMS) who do not need immediate emergency medical care. Secondary objectives were: 1) to evaluate the ability of paramedics to determine hich patients need immediate ambulance transport, and 2) to evaluate on-scene patient characteristics that may aid in developing an EMS transport protocol.

A prospective cross-sectional study design was utilized to estimate the percentage of low-risk patients eligible for non-ambulance transport among 277 patients transported to an emergency department via ambulance. The EMS personnel prospectively rated each patient as to need for immediate ambulance transport. Physician raters, using predefined criteria, determined eligibility for non-ambulance transport.

There were 116 patients (59.2%, 95% CI = 53.4%-65.0%) who were not in need of immediate emergency medical care. Comparison of the EMS personnel's rating with the criterion-standard need for emergency treatment transport yielded a sensitivity of 22.1% (95% CI = 13.9%-30.2%) and a specificity of 80.5% (95%) CI = 72.5%-88.3%). Chief complaints of abdominal pain (OR = 2.94, 95% CI = 1.31-6.60) and administration of oxygen (OR = 2.13, 95% CI = 1.06-4.29) were independently associated with the need for ambulance transport, while young age (OR = 0.28, 95% CI = 0.09-0.90) was negatively associated.

The majority of patients triaged as low-risk were not in need of immediate ambulance transport for emergency medical care. However, EMS personnel, unaided by triage protocols or specific training, could not reliably identify those patients in need of emergency medical treatment, and few factors were identified to assist that decision.