The strength of specific EMS dispatcher questions for identifying patients with important clinical field findings

Introduction. There is growing interest in more efficiently matching emergency medical services (EMS) resources to patient need. Emergency medical services dispatchers may be asked to distinguish between callers with an immediate need for EMS and those who may safely use alternative services. New dispatcher protocols are required or existing protocols must be shown to be reliable for this new task. Objective. To examine whether answers to currently asked dispatcher questions in one urban center can identify callers with important clinical field findings (ICFFs). Methods. Audio recordings of EMS dispatcher-caller conversations within three nature codes (falls, sick, trauma) were retrospectively reviewed. Specifically scripted 'cardinal' questions, asked of all callers, identify what happened, whether the patient is breathing okay, and whether the patient is conscious. 'Key' questions are specific to each nature code and further specify patient circumstances. Compliance with protocol and caller answers were documented. Researchers developed a list of ICFFs that, if present on the corresponding EMS record, were judged to justify an immediate EMS response. Logistic regression was used to analyze the relationship between caller answers and the presence of ICFFs. A p-value of 0.10 was used. Results. Of 430 recordings, 383 (89%) were usable. Falls: 103 (26%); trauma: 136 (37%); sick: 144 (37%). The caller was the patient 41 (11%) times. There were 198 (52%) females in the sample. There was no matching EMS record for 96 (25%) cases. An ICFF was determined to be present in 191 (67%) of the 287 recordings with matching EMS data. Compliance across the cardinal and key questions ranged from 62% to 88%. Age alone was suggestive of a patient who may be identified at dispatch as having an ICFF [adjusted OR 1.01 (90% CI: 0.999-1.025), p < 0.10]. No other key or cardinal questions were related to ICFFs. Conclusion. Cardinal questions are most often asked. Implied or volunteered information is often relied upon to answer key questions. Key questions for certain nature codes are not answered about one third of the time. Increasing age may suggest a stronger likelihood for an ICFF to be identified at dispatch. Otherwise, in this sample, caller answers to currently asked questions do not appear useful if the goal is to identify at dispatch those without an ICFF.