Patients with interhospital stroke transfers had higher mortality, more severe disability than front-door patients

The differing characteristics of patients who are transferred should be accounted for in the quality measurements of receiving hospitals, the study authors suggested.

Patients with acute ischemic stroke who were transferred to specialized stroke centers had more severe strokes on arrival and higher in-hospital mortality compared to those who were admitted directly to such hospitals, a recent study found.

Researchers analyzed 970,390 cases of acute ischemic stroke in the Get With The Guidelines–Stroke registry from January 2010 to March 2014 to determine variation in baseline characteristics and clinical outcomes between patients presenting directly to the front door of stroke centers versus transfers from another hospital. Patients were discharged from 1,646 hospitals in the U.S. Researchers compared hospitals with high transfer-in rates (≥15%) versus those with low transfer-in rates (<5%) and compared the front-door versus transfer-in patients admitted to hospitals with high transfer-in rates. Results were published online on Sept. 1 by Circulation: Cardiovascular Quality and Outcomes.

Overall, 87% of cases initially presented to the ED and 13% were a transfer from another hospital. Hospitals with more transfers in were larger, had a median 31% transfer-in rate among all stroke discharges, had higher annual volume of acute ischemic stroke and intravenous tissue-type plasminogen activator rates, and were more often Midwest teaching hospitals and stroke centers.

Compared to front-door patients, transfer-in patients had higher in-hospital mortality (7.9% vs. 4.9%; standardized difference, 12.4%), were younger, were more often white, had higher median National Institutes of Health Stroke Scale scores, and less often had hypertension and previous stroke/transient ischemic attack. After adjustment for multiple variables, transfer-in patients had higher in-hospital mortality and more severe disability, with higher discharge Modified Rankin Scale scores.

Given these differences, the transfer-in patients “have the potential to negatively influence institutional mortality rates and should be accounted for explicitly in hospital risk-profiling measures,” the authors concluded. They noted that there was also significant regional variability in transfer rates. Limitations of the study include the site-level, retrospective method of data collection, as well as a lack of additional information (e.g., specific reasons for transfer, transfer times), the study authors noted.

“Although [CMS] currently assigns mortality to the hospital where the patient was first admitted, transfers from emergency departments may represent a loophole, wherein first admission occurs at the receiving hospital,” an accompanying editorial noted.

In addition to suggesting an impact of interhospital stroke transfers on hospital mortality metrics, the study findings show an opportunity for quality improvement, although the best model of care remains unknown, the editorial said. “A better understanding of the ins and outs of doors in stroke care will be a big step towards ensuring that the right patients are treated at the right centers and the right time,” the editorialist wrote.