Patient factors play key role in emergency department imaging

Despite concerns to the contrary, very little of the variation in Emergency Department (ED) imaging utilization is attributable to physician experience, training or gender, according to a new study published online in the journal Radiology.

Imaging exams like and CT scans are common in the ED. In 2010, slightly more than 47 percent of all ED visits in the United States had an imaging exam associated with them.

"Analyzing and understanding drivers of use of imaging in the ED is important for several reasons," said Christopher L. Sistrom, M.D., M.P.H., Ph.D., from the departments of radiology at Massachusetts General Hospital in Boston and the University of Florida in Gainesville, Fla. "There's a balance of cost and benefits to the patient, institution and payer, as well as the overarching issue of ."

Previous studies have found substantial variation in imaging rates across and within EDs, suggesting different tendencies among physicians when ordering imaging. However, much of the existing research is limited, according to Dr. Sistrom.

"A lot of literature on imaging variability can lead to a false assumption that doctors are primarily responsible," he said. "The problem is that it is difficult to fully describe and quantify variability at the different levels it can occur."

In the new study, Dr. Sistrom and colleagues analyzed 88,851 ED visits during 2011 at Massachusetts General Hospital. They used an analytical tool known as hierarchical to identify multiple predictors of the probability that imaging was ordered during a given visit.

"That's what makes our paper unique," Dr. Sistrom said. "Hierarchal modeling allows us to ask very specific questions about the relative contributions of various factors to imaging use."

The overall rate of imaging utilization in the Massachusetts General ED was 45.4 percent in 2011, similar to the 2010 national average of 47.2 percent. Analysis of the data revealed that physician-related factors like gender, experience and training did not correlate with imaging use.

"The key finding in our study is that doctors don't make much difference in imaging utilization," Dr. Sistrom said. "Our data showed that doctors are responsible for about one percent of the variability in probability of having an imaging exam during an ED visit."

Instead, patient and visit factors were the predominant predictors of the likelihood of imaging for a given ED visit. These factors include prior visit, referral source, arrival mode and clinical reason for the visit.

The workload of the ED was another significant factor in imaging use. When the ED was the least busy, the odds of low-cost imaging were 11 percent higher than the reference standard. A busier ED resulted in a tendency towards more high-cost imaging.

The new study shows that medical management efforts looking to reduce imaging utilization may be misguided in focusing on remediating ED physicians.

"To reduce imaging utilization, a lot of people in quality improvement and medical management might try to identify high outliers and punish them," Dr. Sistrom said. "In settings like the one we studied, that strategy won't get you anything but angry doctors."

More information: "Use of Imaging in the Emergency Department: Physicians Have Limited Effect on Variation." Radiology, 2013.

add to favorites email to friend print save as pdf

Related Stories

Emergency departments see substantial increase in CT exams

Nov 29, 2010

A new study reports that the use of computed tomography (CT) in the nation's emergency departments is growing exponentially. If the growth trend continues, by 2011, nearly 20 percent of all emergency department (ED) visits ...

Recommended for you

More aging boomers, but fewer doctors to care for them

2 hours ago

By 2030, the last of the Baby Boomer generation will have turned 65 years old, putting the population of "senior boomers" in the United States at approximately 71 million. Currently, only about 7,000 certified geriatricians – ...

UK study examines communication and end-of-life decisions

2 hours ago

For many people, talking about end-of-life decisions can be very difficult. Although making choices about health care at the end of life is an important outcome of these conversations, recent research suggests that talking ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.