We prospectively identified patients who received IVT from July 2014-December 2017, and compared patients with pre-hospital IVT on MSU with patients brought to the ED via a conventional ambulance. The primary outcome was modified Rankin scale score (mRS) of 1 or better at 90 days. Binary logistic regression model of 90-day mRS for 0-1 vs 2-6 was adjusted for age, initial National Institutes of Health Stroke Scale (NIHSS) score, and pre-morbid mRS.

Seventy-eight patients received IVT in the MSU, and 153 patients received IVT in the ED. No significant differences were seen in gender, age, pre-morbid mRS, initial NIHSS, or risk factors between the groups.  MSU patients received IVT 38 minutes earlier from onset, than the ED patients (median 79 vs. 117 minutes, p<0.001). In an unadjusted analysis, the difference in primary outcome between MSU and ED groups was not significant (41% with MSU vs. 29% with ED, p=0.061). After adjustment for age, initial NIHSS score, and premord mRS, the odds ratio for mRS 0-1 at 90 days with IVT on MSU compared to ED was 2.09 (95% confidence interval (CI), 1.02-4.28, p = 0.044). Following adjustment for time from onset to IVT, the effect of MSU on 90-day mRS was attenuated, and no longer significant (odds ratio 1.65, 95% CI, 0.77-3.55, p=0.196).