Fragmented care may increase the likelihood of Medicare beneficiaries receiving four or more CT head scans within a year of an ischemic stroke, according to a study that found regional and racial variability in high-intensity CT use.

Kimon Bekelis, MD, of Dartmouth-Hitchcock Medical Center in Lebanon, N.H., and colleagues assessed the regional variation in high-intensity CT use and Medicare expenditures in the year after an index admission for ischemic stroke in 327,521 Medicare patients. They published their results online April 8 in Circulation: Cardiovascular Quality and Outcomes.

“Although the development of CT represents the single most important advance in diagnostic radiology, and has changed the field of stroke, inefficient use can have detrimental effects,” Bekelis et al wrote. “With their current use, it is estimated that 1.5 percent to 2 percent of all cancers in the United States can be attributed to radiation, largely from CT studies.”

Index events, identified through Medicare fee-for-service claims data, occurred in 2008 and 2009 with follow-up through 2010. They determined the total number of CT scans a patient received, defining four or more as high intensity. They also counted the number of different physicians a patient saw in the year. Outcomes were risk- and price-adjusted.  

The average number of CT scans in a year after admission was 1.94 and 12 percent of patients had four or more CT scans. On average, blacks and Hispanics had 2.14 scans. The average risk-adjusted rate for increased CT scan use was 2.6 percent higher for blacks than whites.

Bekelis and colleagues also discovered a great deal of regional variability.  Rates of increased CT use ranged from 4.6 percent in Napa, Calif., to 20 percent in East Long Island, N.Y. Large urban centers were more likely to have high-intensity CT use.

Mean expenditures were $43,463 but ranged from $31,175 in Salem, Mass., to $61,895 in McAllen, Texas.  

Patients on average saw 20 different physicians within the first year of the index stroke. Patients in the highest quintile of fragmentation were 77 percent more likely to undergo four or more scans than patients in the lowest quintile. Black patients were more likely to see a large number of physicians.  

“Greater fragmentation of care was found to be associated with the observed regional and racial disparities in high-intensity CT use during the year after admission for ischemic stroke,” they wrote. “Visiting several different providers might account for inconsistent medical records and lack of continuity of care, resulting in larger numbers of redundant diagnostic tests with lower yield.”  

Study limitations included the use of administrative data, which may be erroneous and can contribute to indication bias and confounding. Nor could they account for stroke severity and rehabilitation needs. The study identified associations only, but the “the variation here is strongly suggestive of inefficient use of resources,” which may warrant improved postdischarge strategies.