Researchers identify variation in head CT use among ED doctors

A new study by Brigham and Women's Hospital (BWH) researchers found significant variation in the use of head computed tomography (CT) exams among doctors within the emergency department (ED).

The study will be published in the April 2012 issue of The American Journal of Medicine.

With advanced imaging as a driver of increasing health care costs, strategies to reduce variation in head CT use and other high-cost imaging studies may reduce cost and improve quality of care. This study is part of an effort by researchers at BWH to develop strategies for achieving the appropriate use of expensive radiologic exams.

In the current study, researchers investigated whether a head CT was performed in 55,281 patient visits to an adult-only ED throughout 2009. Patient variables included patient age, gender, severity of the emergency, emergency department location, and disease categorization. Physician-specific variables included years in practice and gender.

Overall, 8.9 percent of the visits generated head CT examinations, with per-physician ordering rates ranging from 4.4 percent to 16.9 percent. Researchers did not find any significant correlation between physician age or gender and CT ordering, as described in previous studies.

"Even after accounting for a number of factors associated with ordering behavior, we found that greater than two-fold variability in head CT use still persists," said lead study author Luciano Prevedello, MD, MPH, BWH Center for Evidence-Based Imaging and Department of Radiology.

Patients receiving head CT were more likely to be male, older, and in a more urgent emergency category. Patients with head trauma were more likely to receive a CT, followed by patients with stroke, headache, and other types of trauma.

"The variability may have been due to physician's practice style, knowledge gaps, risk tolerance, or other factors" says Prevedello. "We are currently investigating the impact of real-time evidence-based clinical decision support (embedded in the electronic health record) on variation in test ordering behavior of physicians to improve quality of care and improve appropriateness of testing."

Robert G. Stern, MD, Department of Radiology, University of Arizona College of Medicine, Tucson, a noted expert in the field said, "Attempts to reduce utilization of expensive imaging studies have been made in the past, without any real focus on quality of care and appropriate ordering patterns. Prevedello and his colleagues underscore the need to develop evidence-based systems to reduce costly and inappropriate resource allocations."

Prevedello's study is part of a group of studies led by BWH researchers investigating orders for imaging studies and the use of decision support systems for improving the orders' appropriateness.

For instance, a study by BWH researchers looked at the use of CT pulmonary angiography for the assessment of pulmonary embolism. They found significant reductions in CT pulmonary angiography use, and a corresponding increase in its yield for diagnosing pulmonary embolism, following implementation of computerized decision support systems.

Another BWH study showed the feasibility of implementing such computerized systems at a large hospital. Researchers saw that integrating computerized physician order entry (CPOE) with decision support into the IT infrastructure of the health care enterprise and clinicians' workflow was broadly accepted clinically.