Face Arm Speech Time Test Use in the Prehospital Setting, Better in the Ambulance than in the Emergency Medical Communication Center

Abstract

Background: Prehospital identification of acute stroke increases the possibility of early treatment and good outcome. To increase identification of stroke, the Face Arm Speech Time (FAST) test was introduced in the Emergency Medical Communication Center (EMCC). This substudy aims to evaluate the implementation of the FAST test in the EMCC and the ambulance service. Methods: The study was conducted in the region of Stockholm, Sweden during 6 months. The study population consisted of all calls to the EMCC concerning patients presenting at least one FAST symptom or a history/finding making the EMCC or ambulance personnel to suspect stroke within 6 h. Positive FAST was compared to diagnosis at discharge. Positive predictive values (PPV) for a stroke diagnosis at discharge were calculated. Results: In all, 900 patients with a median age of 71 years were enrolled, 667 (74%) by the EMCC and 233 (26%) by the ambulances. At discharge, 472 patients (52%) were diagnosed with stroke/transient ischemic attack (TIA), 337 identified by the EMCC (71%) and 135 (29%) by the ambulances. The PPV for a discharge diagnosis of stroke/TIA was 51% (CI 47-54%) in EMCC-enrolled and 58% (CI 52-64%) in ambulance-enrolled patients. With a positive FAST the PPV of a correct stroke/TIA diagnosis increased to 56% (CI 52-61%) and 73% (CI 66-80%) in EMCC- and ambulance-enrolled patients, respectively. Positive FAST from EMCC was also found in 44% of patients with a nonstroke diagnosis at discharge. A stroke/TIA diagnosis at discharge but negative FAST was found in 58 and 27 patients enrolled by the EMCC and ambulances, respectively. Conclusions: The PPV of FAST is higher when used on the scene by ambulance than by EMCC. FAST may be a useful prehospital tool to identify stroke/TIA but has limitations as the test can be negative in true strokes, can be positive in nonstrokes, and FAST symptoms may be present but not identified in the emergency call. For the prehospital care situation better identification tools are needed.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

“…21 In another study of 21 760 dispatches for stroke, the positive predictive value of the dispatch stroke/TIA symptoms identification was 34.3% (95% CI, 33.7-35.0), and the sensitivity was 64.0% (95% CI, 63.0-64.9). 22 In both cases, use of a prehospital stroke scale improved stroke identification, but better stroke identification tools are needed in the prehospital setting.…”

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

“…Dispatcher sensitivity = true positives/all hospital confirmed stroke or TIA cases; dispatcher positive predictive value = true positives/all dispatcher suspected stroke or TIA cases; dispatcher specificity = true negatives/all hospital confirmed non-stroke or TIA cases; dispatcher negative predictive value = true negatives/all dispatcher non-suspect stroke or TIA cases. Seven cohort studies (3 prospective [20][21][22] and 4 retrospective [12][13][14]23] ) that enrolled a total of 16,382 patients were included. Study characteristics and dispatcher accuracy data (sensitivity, PPV, specificity, and NPV) are summarized in table 1 .…”

“…Four studies utilized versions of the MPDS, which incorporates screening questions for facial weakness, arm weakness, and speech difficulty [12][13][14]23] . Two studies used the FAST screening tool without mention of using other decision support such as the MPDS algorithms [20,21] . One study employed a novel screening algorithm developed after qualitative review of 207 emergency dispatch calls [22] .…”

Stroke Mimics in a Stroke Care Pathway Based on MRI Screening

“…Cerebral imaging and discharge letter were assessed on our computer system, This score facilitates the prehospital stroke recognition and consists of 3 items (facial weakness, arm weakness and speech disturbance) [14,15] . A FAST score was defined as positive by the presence of at least one of the 3 items.…”