A Multicenter Diagnostic Accuracy Study on Prehospital Stroke Screening Scales

Background: Stroke is one of the most common debilitating diseases. Although effective treatment is available, a golden time has been defined in this regard. Therefore, prompt action is needed to identify patients with stroke as soon as possible, even in the pre-hospital stage. In recent years, several clinical scales have been introduced for this purpose. We performed the present study to examine the accuracy of eight clinical scales in terms of stroke diagnosis. Methods: This multicenter diagnostic accuracy study was conducted in 2019. All patients older than 18 years who were admitted to the emergency department (ED) and underwent brain magnetic resonance imaging (MRI) for a suspected stroke were eligible. All data were gathered through a pre-prepared checklist consisting of three sections, using the clinical records of the patients. The first section of the checklist included basic characteristics and demographic data. The second part included physical examination findings of 19 items related to the 8 scales. The third part was dedicated to the final diagnosis based on the interpretation of brain MRI, which was considered the gold standard for the diagnosis of acute ischemic stroke (AIS) in the current study. Results: The data from 805 patients suspected of stroke were analyzed. In all, 463 patients (57.5%) were male. The participants' age was 6-95 years with a mean age of 66.9 years (SD = 13.9). Of all the registered patients, 562 (69.8%) had an AIS. The accuracy of screening tests was 63.0% to 84.4%. The sensitivity and specificity were 71.9% to 95.7% and 46.5% to 82.8%, respectively. Among all the screening tests, Los Angeles Pre-Hospital Stroke Screening (LAPSS) had the lowest sensitivity, and Medic Pre- hospital Assessment for Code Stroke (Med PACS) had the highest sensitivity. In addition, PreHospital Ambulance Stroke Test (PreHAST) had the lowest specificity and LAPSS had the highest specificity. Conclusion: Based on the findings of the present study, highly sensitive tests that can be used in this regard are Cincinnati Pre-hospital Stroke Scale (CPSS), Face-Arm-Speech-Time (FAST), and Med PACS, all of which have about 95% sensitivity. On the other hand, none of the studied tools were desirable (specificity above 95%) in any of the examined cut-offs.