Abstract 89: Accuracy and Clinical Implications of Cincinnati Pre-hospital Stroke Scale and Los Angeles Pre-hospital Stroke Scale use by Emergency Medical Services

Abstract

Background: Cincinnati Pre-hospital Stroke Scale (CPSS) and Los Angeles Pre-hospital Stroke Scale (LAPSS) are widely used by emergency medical services (EMS) to screen potential ischemic stroke patients. We performed a population based state-wide study to evaluate the accuracy of CPSS and LAPSS in identifying stroke cases and investigate their impact on ischemic stroke treatment. Methods: A statewide EMS database was created by linking South Carolina’s statewide Emergency Department (ED) and hospital discharge records for the calendar years 2010-2012. The EMS data were obtained from the Division of EMS and Trauma at Department of Health Environmental Control and linked to hospitalization records at Office of Research and Statistics. Results from the EMS use of CPSS and LAPSS were compared with hospital discharge diagnoses for stroke. For both scales, we calculated Sensitivity, Specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV). Additionally we evaluated the impact of identification of stroke during EMS transportation by CPSS/LAPSS on treatment of ischemic stroke with intravenous tissue plasminogen activator (IV-tPA). Results: Of all the EMS transported cases between January 2010 and December 2012, use of CPSS or LAPSS was recorded for 101,442 cases. Among the cases where the use of CPSS/LAPSS stroke scale was recorded, 6,757 cases had a diagnosis of ischemic stroke on hospital discharge records. CPSS demonstrated sensitivity of 59%, and specificity of 96%. Sensitivity and specificity for LAPSS were 26% and 84%, respectively. PPV and NPV for CPSS were 45% and 98%, and for LAPSS were 27% and 83%, respectively. Rates of IV-tPA administration were approximately five times higher for those correctly identified by CPSS (18.3% for true positive vs. 3.5% for false negative, P<0.01), and about two higher for those correctly identified by LAPSS (33.3% for true positive vs. 14.9% for false negative, P<0.01). Conclusion: Early identification of potential stroke cases using CPSS/LAPSS can have a significant impact on treatment of ischemic stroke with IV-tPA. We report a modest accuracy of CPSS and LAPSS in correctly identifying stroke cases in the field, with CPSS leading to a better rate of IV-tPA use compared with LAPSS.