Title: Cost-effectiveness of 64-slice computed tomography in cardiac care and an analysis of the adoption and diffusion of a new technology
Description: The 64-slice computed tomography (CT), a recent advance in radiological imaging, has the potential to significantly alter the landscape of cardiac care. As the first scanner with the ability to generate high-resolution images of the coronary arteries--a technique called coronary CT angiography--the device has simultaneously spawned both hope and controversy. Many physicians believe that its coronary imaging, capabilities will improve clinical care, but others argue that the procedure raises cancer risk by exposing patients to high radiation doses and, by uncovering incidental findings, could lead to additional, unnecessary diagnostic tests and costs. Evidence, however, is limited because of the technology's novelty. In this collection of studies, we address some of the uncertainty surrounding 64-slice CT by analyzing its cost-effectiveness in two important clinical scenarios: the triage of patients with acute chest pain in the emergency department, and the screening of patients with stable chest pain in the outpatient setting. We also examine the overall adoption and diffusion of 64-slice CT in the U.S. to better understand how hospitals manage new technologies with unclear implications for incremental health outcomes and costs.

We find that coronary CT angiography with the 64-slice CT may lead to more efficient triage of acute chest pain patients and could save money in patients with a low coronary artery disease (CAD) prevalence. In undifferentiated patients presenting to their primary care physicians with symptoms suggestive of CAD, we find that coronary CT angiography yields modestly improved health benefits, compared to conventional diagnostic strategies. However, these results are sensitive to radiation risks and incidental findings. Finally, we find that hospitals that treat high volumes of ischemic heart disease patients--a population that could potentially benefit from coronary CT angiography--are more likely to adopt 64-slice CT, as are hospitals that are financially healthy. Our results suggest that the device's adoption may be related to efforts to improve quality, but the paucity of evidence informing coronary CT angiography's role in clinical care implies that quality-driven adoption may be premature. Moreover, our finding that adoption is motivated independently by the availability of capital reinforces concerns about haphazard technology acquisition.