Chasing Appropriate CT Use in the ED

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In recent years, radiology as a specialty has dedicated itself to encouraging appropriate utilization of imaging. Limiting unnecessary use trims healthcare costs and, with regard to CT use, cuts the amount of radiation patients receive. Utilization controls look different depending on the setting, and those working in emergency medicine have a unique challenge in their fast-paced, high-stakes environment.

Like CT use overall, the number of CT scans ordered in the emergency department (ED) skyrocketed in the early 2000s, before leveling off towards the end of the last decade. In 1996, just 3.2 percent of emergency patients received CT scans, but by 2007, that number had ballooned to 13.9 percent, according to a University of Michigan Health System study. Over that period, the rate of CT use grew 11 times faster than the rate of ED visits.

Shortly thereafter, the growth of CT in the ED halted. A study of National Hospital Ambulatory Medical Care Survey data published in the November 2013 issue of Annals of Emergency Medicine found the proportion of all U.S. ED visits in which CT was performed was 11.4 percent. For children, the rate was 4.7 percent.

Certain indications more commonly trigger a CT scan. Patients reporting nerve impairments, flank pain, convulsions, vertigo, headache and abdominal pain all received a CT scan at least 25 percent of the time.

Of course, high CT utilization in the ED doesn’t necessarily mean there’s rampant overutilization. But with intense pressure to reduce spending across the U.S. healthcare system and concerns about ionizing radiation, efforts to encourage appropriate use have taken center stage.

High-tech assist from decision support

Clinical decision support (CDS) systems have received much press as a potential silver bullet for utilization management. They are an appealing option for providers weary of dealing with prior-authorization or radiology benefit managers—but do they actually reduce CT use?

Research on CDS has been mixed with regard to effect on utilization, with different types of emergency CT scans being impacted to varying degrees. Use of CDS resulted in a 20 percent reduction of emergency CT pulmonary angiography for acute pulmonary embolism in a study published in the February 2012 issue of Radiology. A separate study, published in January 2011 in the Journal of the American College of Radiology, found similar decreases in the rate of sinus CT for sinusitis. However, that same study found no significant changes in utilization rates for head CT.

While CDS is widely promoted, there’s no guarantee it will reduce CT use versus a physician who uses good judgment, says David T. Schwartz, MD, of New York University School of Medicine in New York City. “It’s nice to have the rules around, but to just say all we have to do is pay attention to the rules and we’ll stop getting all these ‘inappropriate CTs’ is really not true.”

For Stephen M. Ledbetter, MD, MPH, of Harvard Medical School and Brigham and Women’s Hospital in Boston, ensuring there’s a physician with good judgment on hand means 24-hour coverage of the ED by an attending radiologist, rather than relying only on residents for part of the day.

“One of the things to help appropriate utilization and make sure we’re doing the right study at the right place at the right time is to have an expert in imaging actually present in the ED,” he says.

Only 10 percent of academic medical centers have 24-hour coverage seven days a week, according to the most recent survey, published in the October 2007 issue of the Journal of the American College of Radiology. Ledbetter has called on colleagues to establish more comprehensive coverage of EDs as a way of improving patient-centered care. “It’s elevating the way radiology services are provided in the emergency department to the same level that emergency medical care is provided: 24/7 contemporaneous interpretation by board certified attending physicians.”

Managing CT use = managing patients

Aside from rethinking ED staffing, better case management of patients also can reduce inappropriate imaging use in the ED, says Casey A. Grover, MD, emergency medicine resident at Stanford University, and colleagues from the Community Hospital of the Monterey Peninsula, who published a study on the topic in the August 2009 issue of the Western Journal of Emergency Medicine.

Grover and colleagues noticed that a small number of frequent ED visitors made up a large proportion of annual ED visits and emergency diagnostic imaging use. Because frequent visitors to the ED represent either patients who are not being effectively treated or those who are engaged in drug-seeking behavior, a case management system was developed to refer patients with five visits in a month to appropriate outpatient care. The case management team featured physicians, nurses, social services and specialists in pain management and behavioral health.

 A study of 96 frequent ED visitors found that the program reduced reliance on the ED, dropping the average number of visits per patient per month from 2.3 in the six months prior to the program to 0.6 ED visits per patient per month in the six months after enrolling in the program. Prior to case management, this group averaged 25.6 CT images per patient per month, and after the program they averaged 8.1 CT images per patient per month, resulting in a 67 percent decrease in radiation exposure.

Grover notes that the inclusion of social care services in the ED is a developing trend. “I think we’ll see some element of this in the future as people realize that being in the emergency department a lot is cost-ineffective in our stressed healthcare system and this is a way to take care of people.”

The value of high utilization

While EDs continue to chase after appropriate imaging goals, it’s important not to lose sight of the fact that CT use in the ED is effective at ruling out serious, life-threatening conditions. CT is sensitive and specific for many ED diagnoses, and there’s value to a negative study.

CT’s peak in the 2000s brought an awareness of utilization trends and got equipment vendors paying attention to dose and developing scanners with adjustable parameters for dose reduction. The rise of imaging in the ED also reduced the need for other more invasive tests  by offering a quick way for ED physicians to identify the sickest patients.

“There’s really an excessive concentration on how many CTs are ordered, and very little attention is paid to the tremendous benefit they offer for a wide variety of emergency department problems,” says Schwartz.