Introduction: In emergency dispatching, pre-alerts are used to send responders to calls prior to getting a final dispatch code. Some studies have showed that pre-alerts can effectively reduce dispatch time for out-of-hospital cardiac arrests, potentially improving overall patient outcome. However, there is also a potential risk in running lights-and-siren on non-fully triaged calls. Although pre-alerts have been used for several years, no research studies have demonstrated its benefit, in general.
Objectives: The goal of this study was to determine the implications of pre-alerts for medical emergency calls, with regard to dispatch priorities, response units, and call cancellation and call downgrading.
Methods: This retrospective, descriptive study analyzed de-identified dispatch and EMS data from two emergency communications centers in the USA: Johnson County Emergency Communications Center (ECC), Kansas, and Guilford County Emergency Services, North Carolina.
Results: A total of 139,815 calls were included in the study, of which 73,062 (52.3%) were downgraded, and 7,189 (5.1%) were cancelled. This indicates a waste of valuable resources and an implied increase in cost and risk. Additionally, in 20.0% of the calls, at least one response unit was cancelled, while only 1.12% were transported with high priority (lights-and-siren). A median elapsed time (-14 sec) from pre-alert to ProQA launch indicates that calls sat in the queue for median time of 14 seconds before first units were assigned.
Conclusions: The study found a significant number of cancelled units and downgraded calls. In addition, the very small percentage of calls where patients were transported with high priority indicates unnecessary pre-alerts for non-critical patients. Study findings demonstrated that calls spent a substantial amount of time in queue, and units were sent without safety/final coding information. To better establish the positive and negative impacts of pre-alerting, a controlled study