Abstract TP245: Impact Of A County-wide Prehospital Destination Protocol On Thrombolytic Rates For Acute Ischemic Stroke (AIS)

Background: Higher IV t-PA rates were observed statewide after regionalization of stroke. Objectives: We describe the IV t-PA rates in ambulance transported acute ischemic stroke (AIS) patients before and during implementation of a county wide prehospital stroke center destination protocol(SDP)and examine the association between SDP and IV t-PA rates in ambulance transported AIS patients. Methods: This is a cross-sectional observational study of patients with a hospital based diagnosis of AIS identified using validated ICD- 9 codes. Patient records from 2005-2007 were obtained from the discharge abstract file of the statewide administrative database and were linked to the prehospital electronic records using patient level identifiers and probabilistic linkage methodology. Thrombolytic use for AIS was identified using the procedure codes in the discharge database. We excluded direct admissions and inter-facility transfers. IV t\_PA rate by year was calculated.Logistic regression was used to determine association between SDP and the IV t\_PA rate in AIS patients after controlling for patient and hospital demographics, stroke center designation and teaching status of the hospital, patient residence and day of the week using logistic regression. Data analysis was performed using SAS 9.2 Results: During a 3 year period, 6181 patients with a primary or secondary diagnosis of stroke were transported by ambulance. Mean age at time of admission was 74 (+/-15) years; 54% (n=3312) were females and 63% (n=3870) were whites. Majority of patients were treated at stroke centers 4132 (70%) and 6005 (97%) were treated at community hospitals. Among ambulance transports, IV t-PA rate did not increase during the implementation of the stroke center designation protocol (pre protocol phase 2.82%, post protocol phase 2.85%, p value 0.95). After controlling for patient demographics, stroke center status, teaching status of the hospital and the weekend effect, SDP implementation was not independently associated with increased rate of IV t-PA in AIS (OR 0.96, 95 CI 0.63-1.47). Conclusions: Among ambulance transported patients, our preliminary findings do not show an increase in thrombolytic rates during implementation of a stroke center destination program.