Rates, Characteristics, and Outcomes of Patients Transferred to Specialized Stroke Centers for Advanced Care

BACKGROUND: While many patients are transferred to specialized stroke centers for advanced acute ischemic stroke (AIS) care, few studies have characterized these patients. We sought to determine variation in the rates and differences in the baseline characteristics and clinical outcomes between AIS cases presenting directly to stroke centers' front door versus Transfer-Ins from another hospital. METHODS AND RESULTS: We analyzed 970 390 AIS cases in the Get With The Guidelines-Stroke registry from January 2010 to March 2014 to compare hospitals with high Transfer-In rates (>= 15%) versus those with low Transfer-In rates (<5%) and to compare the front-door versus Transfer-In patients admitted to those hospitals with high Transfer-In rates (high Transfer-In hospitals). Of 970 390 patients discharged from 1646 hospitals, 87% initially presented via the emergency department versus 13% were a Transfer-In from another hospital. High Transfer-In hospitals had a median 31% Transfer-In rate among all stroke discharges, were larger, had higher annual AIS volume and intravenous tPA (tissue-type plasminogen activator) rates, and were more often Midwest teaching hospitals and stroke centers. Compared with front-door, Transfer-In patients were younger, more often white, had higher median National Institutes of Health Stroke Scale scores, less often hypertension and previous stroke/transient ischemic attack, and higher in-hospital mortality (7.9% versus 4.9%; standardized difference, 12.4%). After multivariable adjustment, Transfer-In patients had higher in-hospital mortality and discharge modified Rankin scale. CONCLUSIONS: There is significant regional variability in the transfer of patients with AIS. Because Transfer-In patients seem to have worse short-term outcomes, these patients have the potential to negatively influence institutional mortality rates and should be accounted for explicitly in hospital risk-profiling measures.