Performance of a system to determine EMS dispatch priorities

Inappropriate use of emergency medical services (EMS) for nonemergencies strains EMS resources and limits efficiency. Protocol-driven dispatch systems attempt to correct the imbalance that exists between demand and available resources by prioritizing 911 calls. This study compared dispatch priority decisions with apparent patient need, based on emergency department (ED) presentation, by matching 320 ED charts with corresponding EMS dispatch and run information. The priorities assigned by the system based on dispatch information were compared with those assigned by a three-member panel of physicians based on ED presentation. The physicians and dispatchers agreed on the need for advanced life support (ALS) versus basic life support (BLS) transport 74% of the time. There was only 43% agreement on the more detailed 4-level classification system. The system assigned the highest level of dispatch utilizing combined ALS and first responders to a significantly greater degree than did the physicians. It was concluded that protocol systems for setting dispatch priorities utilize EMS resources to a higher degree than actually required based on ED presentation.