Assessing Cost-EffectivenessAnd Value As Imaging Grows:The Case Of Carotid Artery CT
- Laurence C. Baker ( [email protected] ) is a professor of health research and policy and CHP/PCOR fellow in the Department of Health Research and Policy, Stanford University, in California.
- Christopher C. Afendulis is a lecturer in the Department of Health Policy at Harvard Medical School, in Boston, Massachusetts.
- Scott W. Atlas is a senior fellow at the Hoover Institution, a professor of radiology and chief of neuroradiology at the Stanford University Medical Center, and senior fellow by courtesy at the Freeman-Spogli Institute for International Studies at Stanford.
Abstract
Computed tomographic (CT) angiography is an imaging test that is safer and less expensive than an older test in diagnosing narrowing of the carotid arteries—the most common cause of stroke in US adults. Our examination of Medicare data between 2001 and 2005 found that about 20 percent of the time this test was used, it substituted for the older test. The majority of new use, however, constituted “incremental” use, in cases where patients previously would not have received any test. We found no evidence that the growth in CT angiography led to more patients’ being treated for carotid artery disease. The value of the test as a substitute for the older procedure may be enough to still justify expanding use. Tracking the uses of emerging technologies to encourage efficient use is essential, but it can be challenging in cases where new tools have multiple uses and information is incomplete.
