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.