Authors used real world data based on GWTG registry, covering 54,353 patients treated between 2003-2012 at 1395 institutions, and analysed in fifteen minute increments for treatment effects. Across the ninety minute increments (0-90, 91-180, 181-270 minutes) there was no difference in hospital characteristics such as treatment time or volume, treatment rates, or designation as a stroke center. Patients treated in first ninety minutes had higher NIHSS scores (mean 12) than those treated in the 181-270 time frame (mean 9.0). Nonetheless, faster treatment .
Findings based on fifteen minute increments showed less mortality for each 15 minute increment (0.96 OR), and increased odds of independent ambulation at discharge (or 1.03 per 15 minute increment).