Abstract 154: Acute Stroke Recognition by Paramedics after Regionalization of Stroke Care: Outcomes Based Study

Background: Early evidence supports preferential transport of patients with stroke symptoms to primary stroke centers. While validated stroke tools exist for screening of stroke symptoms in the prehospital setting, system wide triage performance of prehospital providers in a regionalized system has not been reported. The objective of this study is to assess the diagnostic ability of prehospital providers, before and after regionalization of care, using outcomes based approach. Methods: This is a cross-sectional study of all patients who were transported to hospitals in two Northern California counties by providers of a single EMS agency during a three year period. One county remained non-regionalized (NR) during the study period and the other initiated and completed regionalization(R) of the system during the study period. Patient demographic data, prehospital provider clinical assessment was obtained from the computerized prehospital transport records and physician diagnosis was obtained from statewide administrative patient discharge data. The data sources were linked using probabilistic linkage methodology. Patients ≥18 years of age with validated ICD- 9 code for stroke were included. We excluded inter-facility transports and direct admissions. Sensitivity, specificity and predictive values for were determined before and after implementation of regionalization. Data analysis was performed using SAS version 9.2. Results: The total number of medical related EMS transports for 3 years was 310,731 and the number of patient discharges with a primary diagnosis of stroke was 10,298. We were able to link 3736 stroke records which indicate EMS use by 36% (3736/10,298) stroke patients. The sensitivity, specificity, PPV and NPV in the pre-regionalization phase was 28%, 80%, 53%, 58% and during the implementation phase of regionalization was 39% 78%,57% and 63% (p <0.05). The performance in the NR County during the entire period was 23%, 76%, 40% and 58%. Conclusions: Diagnostic accuracy remained low although improved prehospital provider performance was observed after regionalization of stroke care.