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

Abstract 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. Objective Determine whether MSU care is associated with better health, utilization, and spending outcomes for patients with suspected acute stroke. Design Retrospective, observational study of Medicare patients transported by MSUs versus traditional ambulances in New York City, from October 2016 to December 2019. Eligibility 167 Medicare patients with suspected acute stroke transported by MSU and 2,518 propensity-score matched controls. Main Outcomes Primary outcomes included length of stay and discharge destination at index hospitalization, as well as risk of repeat hospitalization, number of emergency department visits, total costs of care, and mortality at 1 year. Results Of 167 patients (mean age, 79.9 years;56.3% women) transported by a MSU for suspected acute stroke, 61.1% had an ischemic stroke/TIA, 7.8% had an intracerebral hemorrhage, and 31.1% had a stroke mimic or other diagnosis. Compared to propensity-score matched control patients, MSU patients experienced similar lengths of stay (5.9 vs 6.7 days,p=0.13) and were similarly likely to be discharged to a skilled nursing facility (15.6% vs 15.1%,p=0.86). They had clinically but marginally significant lower rates of mortality at 1 year (21.6% vs 28.4%; difference, 6.8 percentage points [95% CI -13.3 to 0.3,p=0.058). They had similar rates of any repeat hospitalization (24% vs 23.2%,p=0.82) and ED visits without hospitalization (14% vs 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 lower mortality at 1 year. Prospective trials and replication in other regions are warranted.