High CT scan rates not linked to lower mortality rates in stroke patients

New research has found a wide variation in the extensive use of CT scans in elderly stroke patients across hospitals in the U.S., according to findings published online Oct. 29 in Radiology.

The research team, led by Kimon Bekelis, MD, of Dartmouth-Hitchcock Medical Center in New Hampshire, studied patients over the age of 65 who had suffered a hemorrhagic stroke and monitored their follow up care for one year to determine how high CT scan rates were.

Bekelis and colleagues noted a growing concern over potential adverse effects and costs that come with excessive use of CT. “It has been estimated that 0.4 percent of all cancers nationally may be attributable to radiation from CT studies,” study authors wrote.

A total of 53,272 patients with hemorrhagic stroke were identified in the Medicare Claims Data from 2008 to 2009. This cohort data was classified into age, sex, ethnicity and race, and poverty level.

Researchers found the mean number of CT head scans in the year after admission for hemorrhagic stroke was 3.4 and the median was two. The mean one-year mortality rate was 56.9 percent.

Bekelis and team found that across the country, while the patients’ reason for admittance remained similar (hemorrhagic stroke), the difference in intensity of head CT scan use would vary by up to six-fold.

“Considerable variation was shown among the hospitals with the highest volume of hemorrhagic stroke,” the study read.

For example, Hartford Hospital had an average of 9.6 percent rate of CT scans in the year after patients’ strokes, while Northwestern Memorial Hospital averaged 48.1 percent in the follow up year after a hemorrhagic stroke.

“Variability for high-intensity use was observed even within the same city,” researchers wrote, noting that Beth Israel Deaconess Medical Center and Brigham and Women’s Hospital in Boston averaged 18.7 percent and 27.8 percent, respectively.

Additionally, Medicare enrollees visited an average of 19 doctors in the year after a hemorrhagic stroke, with variations across hospitals between 12.8 and 28.1.

“The higher mean number of different physicians consulted was associated with increased high-intensity use of head CT, both nationwide and among the highest-volume hospitals,” Bekelis and colleagues wrote.

The researchers also found that the higher number of CT scans did not equate to decreased mortality over the follow up year.

“The fact that there is so much variation in high-intensity use of head CT suggests a need for coordinated efforts to minimize disparities,” wrote the authors.