The Patterns and Outcomes of Inter-Hospital Transfer Among Medicare Patients with Ischemic Stroke.

ABSTRACT

BACKGROUND AND PURPOSE: Inter-hospital transfer for ischemic stroke is an essential part of stroke system of care. This study aimed to understand the national patterns and outcomes of ischemic stroke transfer. METHODS AND RESULTS: This retrospective study examined Medicare beneficiaries aged ≥65 years undergoing inter-hospital transfer for ischemic stroke in 2012. Cox proportional hazards model was used to compare 30-day and one-year mortality between transferred patients and direct admissions from the emergency department (ED admissions). Among 312,367 ischemic stroke admissions, 5.7% underwent inter-hospital transfer. Using this value as cut-off, the hospitals were classified into receiving (n = 411), sending (n = 559), and low-transfer (n = 1863) hospitals. Receiving hospitals were larger than low-transfer and sending hospitals as demonstrated by the median bed number (371, 189, and 88, respectively, p < 0.001); more frequently to be certified stroke centers (75%, 47%, and 16%, respectively, p < 0.001); and less commonly located in the rural area (2%, 7%, and 24%, respectively, p < 0.001). For receiving hospitals, transfer-in patients and ED admissions had comparable mortality at 30 days (10% vs 10%; adjusted HR [aHR]=1.07; 95% CI, 0.99-1.14) and 1 year (23% vs 24%; aHR=1.03; 95% CI, 0.99-1.08). For sending hospitals, transfer-out patients, compared to ED admissions, had higher mortality at 30 days (14% vs 11%; aHR=1.63; 95% CI, 1.39-1.91) and 1 year (30% vs 27%; aHR=1.33; 95% CI, 1.20-1.48). For low-transfer hospitals, overall transfer-in and transfer-out patients, compared to ED admissions, had higher mortality at 30 days (13% vs 10%; aHR=1.46; 95% CI, 1.33-1.60) and 1 year (28% vs 25%; aHR=1.27; 95% CI, 1.19-1.36). CONCLUSIONS: Hospitals in the US, based on their transfer patterns, could be classified into 3 groups that shared distinct characteristics including hospital size, rural vs urban location, and stroke certification. Transferred patients at sending and low-transfer hospitals had worse outcomes than their ED admission counterpart.