Association of Mobile Stroke Unit Care and Spending, Utilization, and Death in New York City

Background: Transport by mobile stroke units (MSUs), which provide access to computed tomography scanning and intravenous blood pressure medications and thrombolytics, reduces time to treatment and may improve short-term functional outcomes for patients with acute stroke. The longer-term clinical and financial impacts remain incompletely understood. The aim of the study was to determine whether MSU care is associated with better health, utilization, and spending outcomes for patients with suspected acute stroke.

Methods and results: This was a retrospective, observational study of Medicare patients transported by MSUs versus traditional ambulances in New York City, from October 2016 to December 2019. The study included 167 Medicare patients with suspected acute stroke transported by MSU and 2518 propensity score-matched controls. Primary outcomes included length of stay and discharge destination at the index hospitalization, as well as risk of repeat hospitalization, number of emergency department visits, total costs of care, and death at 1 year. Of 167 patients (mean age, 79.9 years; 56.3% women) transported by an MSU for suspected acute stroke, 61.1% had an ischemic stroke/transient ischemic attack, 7.8% had an intracerebral hemorrhage, and 31.1% had a stroke mimic or other diagnosis. Compared with propensity score-matched control patients, MSU patients were significantly more likely to receive tissue-type plasminogen activator (49.9% versus 9.4%; difference, 37.5 percentage points [95% CI, 30.2-45.6]; P<0.001) but experienced similar lengths of stay (5.9 versus 6.7 days, P=0.13) and were similarly likely to be discharged to a skilled nursing facility (15.6% versus 15.1%, P=0.86). At 1 year, MSU patients had a mortality rate of 21.6%, and control patients had a mortality rate of 28.4%, although the difference did not reach statistical significance (difference, 6.8 percentage points [95% CI, -13.3 to 0.3]; P=0.058). They had similar rates of any repeat hospitalization (24% versus 23.2%, P=0.82) and emergency department visits without hospitalization (14% versus 12%, P=0.86), and there were no significant differences in total spending or specific types of spending.

Conclusions: In this study of patients presenting with suspected acute stroke in New York City, transport by MSUs, compared with traditional ambulances, was associated with a trend toward a lower mortality rate at 1 year. Prospective trials and replication in other regions are warranted.