Dispatcher Stroke Recognition Using a Stroke Screening Tool: A Systematic Review.

Background: Emergency dispatchers represent the first point of contact for patients activating an acute stroke response. Accurate dispatcher stroke recognition is associated with faster emergency medical services response time; however, stroke is often unrecognized during initial emergency calls. Stroke screening tools such as the Cincinnati Prehospital Stroke Scale have been shown to improve on-scene stroke recognition and thus have been proposed as a means to improve dispatcher accuracy. We conducted a systematic review of the accuracy of emergency dispatcher stroke recognition when employing stroke screening tools.

Methods: We conducted a comprehensive search of Medline, EMBASE, CINAHL, and Cochrane databases to identify studies of dispatcher stroke recognition accuracy. Those that specifically reported dispatcher utilization of any validated stroke screening tools in isolation or in the context of a comprehensive screening algorithm such as the Medical Priority Dispatch System (MPDS) were potentially eligible. Studies that reported data sufficient for calculation of dispatcher sensitivity or positive predictive value (PPV) using a hospital-based stroke/transient ischemic attack diagnosis as the reference standard were included. Two independent reviewers determined study eligibility, assessed quality using the QUADAS 2 instrument, and abstracted data.

Results: We identified 1,413 potential studies; 54 underwent full text review. Three retrospective and 4 prospective cohort studies enrolling a total of 16,382 patients met the inclusion criteria. Stroke screening tools included MPDS (n = 4), Face Arm Speech Time (n = 2), and a novel screening algorithm developed after analysis of emergency calls for stroke (n = 1). Regardless of the screening tool employed, dispatcher stroke recognition sensitivity was suboptimal (5 studies, range 41-83%) as was the PPV (7 studies, range 42-68%). Primary study limitations included application of variable reference standards and questions regarding exclusion of subjects. No studies directly compared stroke screening algorithms and no studies specifically examined stroke recognition among potential candidates for acute stroke therapies.

Conclusion: Even when utilizing a stroke screening tool, the accuracy of stroke recognition by emergency dispatchers was suboptimal. More research is needed to identify the causes of poor dispatcher stroke recognition and should focus on potential candidates for time-dependent stroke treatment.