The Prehospital Ambulance Stroke Test vs. the Cincinnati Prehospital Stroke Scale: a diagnostic accuracy study

Introduction Immediate diagnosis of stroke is crucial in reducing its morbidity and mortality rate. There are various pre-hospital assessment tools, such as the Prehospital Ambulance Stroke Test (PreHAST) and the Cincinnati Prehospital Stroke Scale (CPSS) used to identify stroke early in the chain of care. The aim of this study is to compare the accuracy of PreHAST with CPSS in diagnosing stroke. Methods In this diagnostic accuracy study patients with suspicion of stroke were included in this study. In CPSS, the criterion used to indicate stroke are facial droop, speech and arm drift. In PreHAST it is eye position, visual field, facial palsy, right and left arms paresis, right and left legs paresis, sensory and speech. After data collection, sensitivity and specificity were calculated using standard formulae. Different cut-off points for the best diagnostic accuracy were examined in both CPSS and PreHAST. Results In this study, 883 patients were investigated. The results demonstrated that in CPSS, the highest specificity and sensitivity was for facial droop (84.9%) and arm drift (82.7%); and in PreHAST it was eye position (99.6%) and facial palsy (49.2%). The best predictor of stroke in CPSS with highest sensitivity (78.5%) and specificity (66%) was a cut-off point of 1.5 (AUC: 0.744) (p<0.01(. In PreHAST, the highest sensitivity (68.4%) was a cut-off point of 2.5 and the highest specificity (90.2%) was a cut-off point of 5.5 (AUC: 0.775) (p<0.01). Conclusion Both PreHAST and CPSS are useful screening tools in the pre-hospital diagnosis of stroke. In addition to high sensitivity, these tests provide a grading system in which higher cut-off points lead to higher specificity.