Prospective, Multicenter, Controlled Trial of Mobile Stroke Units
Authors: James C. Grotta, Jose-Miguel Yamal, Stephanie A. Parker, Suja S. Rajan, Nicole R. Gonzales, William J. Jones, Anne W. Alexandrov, Babak B. Navi, May Nour, Ilana Spokoyny, Jason Mackey, David Persse, Asha P. Jacob, Mengxi Wang, Noopur Singh, Andrei V. Alexandrov, Matthew E. Fink, Jeffrey L. Saver, Joey English, Nobl Barazangi, Patti L. Bratina, Michael Gonzalez, Brandi D. Schimpf, Kim Ackerson, Carla Sherman, Mackenzie Lerario, Saad Mir, Jenny Im, Josh Z. Willey, David Chiu, Michael Eisshofer, Janice Miller, David Ornelas, James P. Rhudy, Kevin M. Brown, Bryan M. Villareal, Marianne Gausche-Hill, Nichole Bosson, Greg Gilbert, Sarah Q. Collins, Kelly Silnes, Jay Volpi, Vivek Misra, James McCarthy, Tom Flanagan, Chethan P.V. Rao, Joseph S. Kass, Laura Griffin, Nicole Rangel-Gutierrez, Edgar Lechuga, Jonathan Stephenson, Kenny Phan, Yvette Sanders, Elizabeth A. Noser, Ritvij Bowry
Journal: New England Journal of Medicine (2021)

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).