What research has been conducted on the use of a stroke assessment tool by first aid providers, including EMS dispatch personnel?
In 1 study, the positive predictive value for a hospital discharge diagnosis of stroke/transient ischemic attack (TIA) among 900 cases for which EMS dispatch suspected stroke was 51% (95% CI, 47 54), and the positive predictive value for ambulance personnel impression of stroke was 58% (95% CI, 52 64).23 In another study of 21760 dispatches for stroke, the positive predictive value of the dispatch stroke/TIA symptoms identification was 34.3%. In both cases, use of a prehospital tool for stroke screening improved stroke identification, but better stroke identification tools are needed in the prehospital setting. See Table I in online Data Supplement 1.