Comparison of the medical priority dispatch system to an out-of-hospital patient acuity score.

Background: Although the Medical Priority Dispatch System (MPDS) is widely used by emergency medical services (EMS) dispatchers to determine dispatch priority, there is little evidence that it reflects patient acuity. The Canadian Triage and Acuity Scale (CTAS) is a standard patient acuity scale widely used by Canadian emergency departments and EMS systems to prioritize patient care requirements.

Objectives: To determine the relationship between MPDS dispatch priority and out-of-hospital CTAS.