The characteristics of stroke patients not initially identified during emergency prehospital assessment: A systematic review

Background Around 25% of stroke patients do not present with typical ‘Face, Arm, Speech’ symptoms at onset, and are challenging for emergency medical services (EMS) to identify. The aim of this systematic review was to identify the characteristics of acute stroke presentations associated with inaccurate EMS identification (false negatives). Method We performed a systematic search of MEDLINE, EMBASE, CINAHL and PubMed from 1995 to September 2019 using key terms: stroke, Emergency Medical Services, paramedics, identification and assessment. Studies included: Stroke patients or patient records; ≥ 18 years, any stroke type; prehospital assessment undertaken by health professionals including paramedics or technicians; data reported on prehospital diagnostic accuracy and/or presenting symptoms. Data were extracted and study quality assessed by two researchers using the Quality Assessment of Diagnostic Accuracy Studies version 2 (QUADAS-2) tool. Results Of 845 studies initially identified, 21 observational studies met the inclusion criteria. Of the 6934 stroke and Transient Ischaemic Attack (TIA) patients included, there were 1774 (26%) false negative patients (range from 4 (2%) to 247 (52%)). Commonly documented symptoms in false negative cases were speech problems (n=107; 13% to 28%), nausea/vomiting (n=94; 8% to 38%), dizziness (n=86; 23% to 27%), changes in mental status (n=51; 8% to 25%) and visual disturbance/impairment (n=43; 13% to 28%). Conclusion Speech problems and posterior circulation symptoms were the most commonly documented symptoms amongst stroke presentations that were not correctly identified by EMS (false negatives). However, the addition of further symptoms to stroke screening tools requires valuation of subsequent sensitivity and specificity, training needs, and possible overuse of high priority resources.