Abstract 164: Treatment Differences in Acute Stroke By Mode of Transport

Background: EMS ( Emergency Medical Services) is an important component of the stroke chainof survival. While in hospital stroke time targets have shown to be better when prehospital providers provide advance notification, population-wide studies on thrombolysis rates (IV t-PA) for those who arrive by EMS is sparse. Objective: To examine differences in treatment rates for acute stroke by mode of transport. 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. Patient demographic data, prehospital provider clinical assessment was obtained from the computerized prehospital transport records and patient location, hospital demographics, physician diagnosis and treatment rates were 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. Results: Of 10,456 patients who had a hospital based discharge diagnosis of stroke, 3787 (36%) were transported by EMS. Mean age at the time of admission was 75 years (+/- 14); 55% (2093) were females, 65% (2471) were whites and 86% (3247) were Hispanics. Most of the patients had Medicare (72%, 2737) and 92% (3471) were transported from home. Majority of the patients were treated at stroke centers [n=3014, (80%)]) and at community hospitals[n=3664, (97%)]. Of 3757 patients with a primary diagnosis of stroke, 4% (150) were treated with IV t-PA. After controlling for covariates, patients transported by EMS had higher odds of treatment with IV t-PA (OR 2.6, 95 CI 1.9-3.3). Treatment at stroke centers (OR 1.5, 95 CI 1-2.2) and academic centers were independently associated with treatment rates (OR 2.4, 95 CI 1.6-3.6). Conclusions: Arrival by EMS to emergency department is associated with higher treatment rates with thrombolytics for acute stroke patients and efforts should be targeted to improve use of EMS for stroke.