Abstract W P220: Use Of A Prehospital Stroke Scale Increases Accuracy Of Emergency Medical Services Stroke Recognition

Abstract

Background: Prehospital activation of in-hospital stroke response depends on accurate Emergency Medical Services (EMS) provider stroke recognition. While screening tools such as the Cincinnati Prehospital Stroke Scale (CPSS) have been validated, their real world impact is less clear. We determined the accuracy of prehospital stroke recognition and its relationship to CPSS documentation in a cohort of EMS transported suspect and confirmed stroke patients. Methods: We identified a prospective cohort of all suspected or confirmed ischemic stroke or transient ischemic attack (TIA) patients transported by EMS to a large primary stroke center. Data on prehospital and hospital care were abstracted from medical records. The sensitivity and positive predictive value (PPV) of EMS stroke recognition were calculated using the final hospital discharge diagnosis of ischemic stroke or TIA as the gold standard. We compared the sensitivity and PPV of EMS recognition among cases with and without a documented CPSS using chi square tests. We performed multivariable logistic regression analysis to determine the independent relationship between CPSS use and the odds of EMS stroke recognition among confirmed stroke and TIA cases. Results: Over a 12 month period, 434 EMS transported patients met inclusion criteria. The median age was 78 and 60% were female. EMS transported 371 (85.5%) patients as suspect strokes and documented a CPSS in 343 (79.0%). A total of 246 cases (56.7%) were confirmed ischemic strokes (n=186) or TIA (n=60). The sensitivity of EMS stroke recognition was 74.4% (95% CI 68.9 to 79.8) and PPV was 49.3% (95% CI 44.2 to 54.4). Sensitivity was higher among cases with CPSS documentation than without (85.9% vs. 25.5% p<0.0001) as was the PPV (54.3% vs. 21.4%, p<0.0001). After adjustment for age, sex, stroke severity, dispatch reason, and time from symptom onset, CPSS use was associated with substantially higher odds of EMS stroke recognition (OR 19.04, 95% CI: 7.95 to 45.59). Conclusion: EMS providers recognized three quarters of all stroke or TIA admissions, while EMS suspicion of stroke was correct only half of the time. Documentation of a CPSS was associated with substantially higher EMS stroke recognition.