Stroke mortality and readmissions depend on various factors

As part of the Centers for Medicaid & Medicare Services (CMS) value-based purchasing program, more than 3,500 hospitals report their 30-day mortality rates and other measures. The hospitals are paid in part based on the quality of care they deliver. They receive extra money or have their payments reduced based on their outcomes.

A recent study shows that one of the measures CMS uses (stroke mortality) may depend not only on the skills of the hospitals and physicians but also the type of patients they treat.

The researchers found that patients with acute stroke who transferred hospitals had significantly higher rates of in-hospital mortality and in-hospital complications compared with those who were not transferred. They published their results online in Circulation: Cardiovascular Quality and Outcomes on April 12.

Although the analysis was limited to 16,202 acute stroke admissions to 36 hospitals in Michigan from 2009 to 2011, the findings suggested to the researchers that hospitals that receive more transfers may have poorer outcomes simply based on their patient population.

“Our findings that transfer patients had poorer outcomes even after adjusting for case-mix confounding factors—including ischemic stroke severity—also emphasizes the need to continue to improve risk adjustment procedures used for hospital profiling of stroke outcomes,” the researchers wrote. “Moreover, it seems prudent to include transfer status in all risk adjustment models, especially if stroke severity cannot be satisfactorily accounted for.”

The researchers acknowledged their study had limitations. The registry does not collect data on patient outcomes post-discharge such as disability, quality of life, stroke recurrence, hospitalization or survival. In addition, the results may not be generalizable to other hospitals.

Still, previous research has shown that mortality rates depend on various factors, not just the abilities of hospitals and physicians. The researchers offered a few suggestions for future studies.

“Because it is unlikely that the impact of transfers will ever be tested in a randomized design, accurate assessment of the relative benefits and risks of interhospital transfer will need to rely on advanced statistical methods, which in turn will rely on having access to more detailed data on the clinical factors associated with the decision to transfer a particular patient,” they wrote. “Given the importance of interhospital transfers to comprehensive stroke centers, it is surprising how few of the comprehensive stroke centers’ performance metrics address aspects specific to transfer patients. Consideration should be given to developing a comprehensive set of performance metrics that are specific to transferred patients.”

-Tim Casey
Executive Editor