Scrutiny over CT Utilization Creates a Conundrum for Emergency Physicians

Gregg Miller , MD

Chief Medical Officer

Published September 04, 2013

As the cost of healthcare rises, Centers for Medicare & Medicaid Services (CMS) has cast a suspicious eye on certain expensive procedures. One such culprit is emergency department CT scanning, a practice which has skyrocketed in recent years.

From 1995 to 2007, the number of ED visits in which a CT scan was performed increased by 600 percent. However, this hasn't led to a proportionate increase in diagnoses. The number of brain bleeds, tumors, kidney stones and cases of appendicitis diagnosed has remained constant. As a result, some people have concluded — particularly CMS policymakers and the health system administrators that answer to them — that physicians are performing far too many inappropriate scans.

This idea may have a grain of truth. In our current litigious climate, the constant threat of lawsuits leads many physicians to order scans even when the necessity is questionable. This "overprotective" behavior generates more fee-for-service reimbursements for the hospital, so, healthcare administrators have little incentive to discourage or regulate the practice of emergency room CT scanning.

However, there is every indication that this climate is about to change. Our healthcare system is moving toward new models of capitated care, resulting in increased pressure on physicians to limit the use of costly diagnostics. Furthermore, CMS is beginning to include CT utilization metrics in its Core Measures. While their proposed ED measure tracking CT for atraumatic headaches was withdrawn, it's inevitable that we'll see more imaging utilization measures in the future.

Increased CT utilization has certainly resulted in some real benefits for patients. For example, the negative rate for appendectomies has fallen from 20 to 30 percent in the 1990s to just 5 percent today. And CT's diagnostic power makes it easier to triage patients so that less acute cases can be safely discharged. In fact, results of a two-year study at Massachusetts General Hospital suggest that CT scanning reduced the number of patients admitted from the ED by approximately half.

But for all its power as a diagnostic tool, CT scanning has its down sides. Risk of lawsuits, for one. As mentioned above, physicians tend to order CT scans as way to reduce their own liability, and in many cases this is perfectly appropriate. However, we also need to be mindful that there is a direct relationship between hours spent in the ED and patient dissatisfaction. Patients who wait hours for a scan may get angry, and may even sue if sufficiently provoked. In such cases, ordering a scan actually increases the physician's risk.

Overutilization of CT scanning also increases risk by tying up scarce resources. As emergency physicians, we've all had patients who are clearly in serious trouble and need a scan right away. However, if the scanner is tied up with less acute cases (the ones we're checking over "just in case"), life-saving treatment may be delayed. Our actions to slightly decrease risk in a low-acuity patient might markedly increase risk in a high-acuity patient.

Finally, for all of its diagnostic benefits, CT scanning poses risks in the form of radiation exposure. The risk is especially high for children, who due to their small body size receive more radiation per unit dose. A 2013 study in JAMA pediatrics estimated that the 4 million pediatric scans performed annually in the United States could lead to 4,870 future cancers.

Given these realities, how can EDs respond to the coming challenge to reduce CT utilization? The first step is to develop systems for collecting accurate data on CT utilization practices from electronic medical records. Physicians can't change their behavior unless they know where they are and where they need to go.

Second, we need to understand the context for our data. It isn't enough to know that Physician A orders a lot more scans than Physician B. Maybe Physician A sees a sicker patient mix (because she works nights, for example).

Likewise, positive rates can be a clue to whether a physician is utilizing CT appropriately, but they don't tell the whole story. If Physician A's positive rate is better than Physician B's, it could mean that A is using better clinical judgment. But it could also mean that she's ordering scans when she's already fairly certain of the diagnosis.

All of this boils down to a simple truth: it's very hard to determine the appropriateness of a CT scan. There's a lot of complexity involved in analyzing this data, and if we're going to be reporting it, it needs to be taken with a grain of salt. Perhaps the best approach is to compare physicians who work closely together rather than relying on external or national benchmarks. Every ED is unique, and comparisons will be more meaningful among physicians practicing together in the same environment.

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