Outpatient imaging: Assessing the performance of U.S. hospitals

14 billion dollars—that’s how much the use of outpatient imaging services costs for Medicare beneficiaries each year, according to the Centers for Medicare and Medicaid Services (CMS). That figure is driving change throughout the medical imaging industry, with an increased emphasis on quality and efficiency at the forefront of efforts to curb wasteful spending on outpatient imaging services and avoid unnecessary patient exposure to radiation. But what determines what is or isn’t “efficient” when it comes to outpatient imaging facilities?

Since 2009, every hospital in the country has collected and reported data pertaining to outpatient imaging to CMS under the Hospital Outpatient Quality Reporting Program (OQR).  Mandated by the Tax Relief and Health Care Act of 2006, the Hospital OQR is an incentivized reporting program meant to evaluate the state of America’s outpatient services and reward facilities that meet certain criteria for quality and standards of care.

The program includes six explicit efficiency measures related to the use of medical imaging on an outpatient basis. According to CMS, these standards are designed to “reduce unnecessary exposure to contrast materials and/or radiation, ensure adherence to evidence-based medicine and practice guidelines, and promote efficiency defined as ‘absence of waste.’” The measures address six specific types of outpatient imaging:

  • Combination abdominal CT;
  • Combination chest CT;
  • Simultaneous brain/sinus CT;
  • Lumbar spine MRI (for back-pain);
  • Mammography follow-up screenings; and
  • Preoperative cardiac-risk imaging.

While there are some exceptions, lower frequency percentages among these tests generally mean a provider is efficient in its use of imaging, which in turn means a more complete annual update to a facility’s prospective outpatient payment rate. That fact alone, coupled with the program’s already lofty goals of reducing waste and ensuring patient health, means there is a lot riding not just on the performance of individual hospitals, but on the Hospital OQR’s imaging measures themselves.

For this reason, it’s extremely important to measure the measuring stick, says Andy Rosenkrantz, MD, MPA, of NYU Langone Medical Center. “A lot of resources are going into collecting and reporting these measures, and it is intended that stakeholders will make actual decisions based on the data,” Rosenkrantz told Health Imaging. “Patients may in part make a choice about where to seek care, payers and regulators may construct new policies, and hospitals may pursue quality improvement initiatives based on what the data show. So a formal analysis of what the data is actually showing is useful.”

Rosenkrantz and his colleague Ankur Doshi, MD, devised a study to evaluate how well the measures actually are at assessing the overall efficiency of imaging facilities. Using data from the Hospital OQR, they analyzed hospital performance in terms of outpatient imaging frequency in tests highlighted by the measures and compared them with other hospital characteristics.

The results, published in the February issue of the Journal of the American College of Radiology, showed the median frequency for lumbar spine MRI for low back pain as 36.7 percent. All of the other measured studies had frequencies ranging from 1.6 percent to 7.8 percent. Rosenkrantz and Doshi did note some extreme outliers, such as maximal frequencies of 79.2 percent to 95.2 percent for mammography follow-up and combination chest and abdominal CT.

Ultimately, though, the researchers concluded that the Hospital OQR imaging measures are only partially effective in assessing which hospitals make efficient use of outpatient imaging overall and which ones do not. Few correlations were found among measures, except for combination abdominal and chest CT.

“The metrics do seem to be able to show a small fraction of hospitals that are outliers in terms of having much less favorable performance than other hospitals in the nation,” Rosenkrantz said. “At the same time, it isn't really possible to identify top performing hospitals based on the data.”

As the medical imaging industry continues to incentivize efficiency while emphasizing a greater goal of reducing wasteful spending and exposure through excessive imaging, Rosenkrantz believes more tools— and teamwork—are needed to truly evaluate the outpatient imaging performance of our nation’s hospitals. “There does seem to be a role for alternative metrics,” he adds, “potentially designed through a collaboration that brings together radiologists, physicians in other specialties, as well as policy makers.”