Prospective determination of medical necessity for ambulance transport by paramedics

It has been estimated that between 11% and 61% of ambulance transports to emergency departments are not medically necessary. This study's objective was to analyze paramedic ability to determine the medical necessity of ambulance transport to the emergency department.

Paramedics prospectively assessed adult patients transported to an emergency department during a six-week period. The setting was an urban, all advanced life support, public utility model emergency medical services (EMS) system with 58,000 transports per year. Paramedics determined medical necessity of patient transport based on the following five criteria: 1) need for out-of-hospital intervention; 2) need for expedient transport; 3) potential for self-harm; 4) severe pain; or 5) other. On arrival in the emergency department, the emergency physician made a blinded determination based on the same criteria. Kappa statistics were used to assess agreement.

Data forms were completed on 825 of 1,420 (58%) patients transported. Emergency physicians determined 248 (30%) transports were not necessary, paramedics 236 (29%), with agreement in 76.2% (K=0.42) of cases. Paramedics undertriaged 92 patients (11%). Rates of agreement on the five criteria were: 1) 71.9% (K=0.43); 2) 77.7% (K=0.22); 3) 89.6% (K=0.40); 4) 89.6 (K=0.32); and 5) 82.2% (K=0.29).

Paramedics and emergency physicians agreed that a significant percentage of patients did not require ambulance transport to the emergency department. Despite only moderate agreement regarding which patients needed transport, the undertriage rate was low.