Predictors of Increased Intravenous Tissue Plasminogen Activator Use Among Hospitals Participating in the

Background—We sought to determine if intravenous tissue plasminogen activator (IV tPA) use for acute ischemic stroke increased in Massachusetts in association with the Primary Stroke Service program, a statewide stroke center designation and quality improvement initiative. Methods and Results—We analyzed prospectively acquired data from the Massachusetts Department of Public Health between October 2004 and June 2008, including 10 045 consecutive emergency department–based acute ischemic stroke encounters arriving 3 hours after stroke onset at 69 participating Massachusetts PSS hospitals. The overall rate of IV tPA use was 854 of 3866 (22.1%) of patients arriving 2 hours of symptom onset. IV tPA use increased steadily from 2005 (the first full year of the program) to 2008 (18.4%, 21.9%, 22.6%, 25.5%; P0.001). Patients treated with IV tPA were more likely to be younger (72.314.1 versus 74.714.0 years, P0.005) and to have presented after emergency medical services rerouting in July 2005 (96 % versus 94%, P0.009). Patients who arrived at hospitals with a performance achievement award from the Get With The Guidelines-Stroke program were more likely to receive IV tPA after versus before award recognition (28.1 % versus 22.3%, P0.001). Conclusions—In this nearly complete capture of statewide data, rates of IV tPA improved significantly in Massachusetts from 2005 to 2008 in association with a state Primary Stroke Service designation program. Further studies are needed to confirm that treatment disparities exist for older acute ischemic stroke patients and that the rates of thrombolysis hav