Specialized Mobile Stroke Units Decreased Risk of Long-Term Disability

Heinrich Audebert, MD

A new study from investigators in Germany suggests creation and implementation of specialized mobile stroke units could have a dramatic impact on global function following a stroke.

While the city of Berlin has been using these mobile units, called STEMOs (Stroke-Einsatz-Mobile), for years, results of the nonrandomized, the intervention trial indicates patients for whom these units were dispatched experienced higher rates of survival without long-term disability than their counterparts receiving standard care.

"In our study, dispatch of a mobile stroke unit was linked to increased survival and reduced risk of disability," said senior investigator Heinrich Audebert, MD, Professor in the department of neurology and Center for Stroke Research at Charité – Universitätsmedizin Berlin, in a statement. “The relative odds of these patients having significant disabilities three months after stroke was 29 percent lower than in patients cared for by the conventional emergency medical services. STEMO dispatch therefore results in significantly more stroke patients returning to an independent life after stroke."

Developed in conjunction with the Berlin Fire Department, the mobile stroke units were launched in February 2011 with the aim of providing diagnosis and treatment procedures to stroke patients in a more timely manner. Of note, these mobile units are sent in addition to a conventional ambulance, not as a replacement for these vehicles.

Designed to bring necessary tools and instruments to patients sooner after a stroke event, mobile stroke units were equipped with a CT scanner and the ability to perform point-of-care laboratory testing and thrombolysis. and staffed by a paramedic, a radiology technician with emergency training, and a neurologist with training in emergency medicine.

In an effort to demonstrate the effects of implementing similar interventions, investigators designed their study as a prospective, nonrandomized, controlled intervention study and conducted from February 1, 2017 through October 30, 2019. As per study design, emergency dispatchers simultaneously dispatched a mobile stroke unit and ambulance. If a mobile stroke unit was not available, these patients were identified as controls for the investigators’ analysis.

The primary outcome of the study was the distribution of modified Rankin Scale (mRS) scores at 3 months. Additionally, investigators included a 3-tier disability scale at 3 months as a coprimary outcome.

In total, 1543 patients were identified for included in the primary analysis, including 749 who received care from a mobile stroke unit and 794 who received care from a conventional ambulance. The mean age of the study cohort was 74 years and 47% were women. Additionally, 87% had available mRS scores and 98% had information available related to the 3-tier disability scale assessment.

Upon analysis, patients with a mobile stroke unit dispatched had lower median mRS scores at month 3 (3; IQR, 0-3) than their counterparts without a mobile stroke unit dispatched (2; IQR, 0-3) (OR, 0.71; 95% CI, 0.58-0.86; P <.001).

Furthermore, patients who had a mobile stroke unit dispatched had lower 3-month coprimary disability score. In comparison, more patients who had no to moderate disability in the mobile stroke unit group (80.3% vs 78%) while fewer patients had severe disability or died (7.1% vs 8.8%). Investigator noted this translated to a 27% lower odds of a worse functional outcome when a mobile stroke unit was dispatched (OR, 0.73; 95% CI, 0.54-0.99; P=.04).

This study, “Association Between Dispatch of Mobile Stroke Units and Functional Outcomes Among Patients With Acute Ischemic Stroke in Berlin,” was published in JAMA Network.