In a recent study (see below poster), the Montgomery County Hospital District EMS service found that the Medical Priority Dispatch System’s Stroke Diagnostic Tool (SDxT) was able to identify true strokes—those confirmed by the receiving hospital—with a high degree of sensitivity and a comparable specificity to the face-to-face paramedic-initiated stroke activation (PISA).  

The study found a sensitivity of 87.2% for the SDxT, and a specificity of 36.7%. These results were remarkably similar to a 2016 study done by IAED researchers, which demonstrated a sensitivity of 86.4%, and a specificity of 26.6%.¹

 Interestingly, this recent study done by the researchers at Montgomery County Hospital District (MCHD) EMS used only cases where the SDxT yielded a result of ‘clear evidence’ for stroke as its predictor, while the previous IAED study used all cases where stroke evidence was found at all levels (clear, strong, and partial evidence). This difference in study design suggests that modifications to the SDxT in recent years have improved the predictive ability of the SDxT. 

The MCHD EMS research will be showcased at Navigator 2025 in Orlando, FL, April 13-15.  

References

1. Clawson JJ, Scott G, Gardett I, Youngquist S, Taillac P, Fivaz C, Olola C. Predictive Ability of an Emergency Medical Dispatch Stroke Diagnostic Tool in Identifying Hospital-Confirmed Strokes. J Stroke Cerebrovasc Dis. 2016 Aug;25(8):2031-42. doi: 10.1016/j.jstrokecerebrovasdis.2016.04.021. Epub 2016 May 30. PMID: 27256173.