Health Affairs: MRI abundance may lead to excess in back surgeries
MRI is frequently used to evaluate lower back pain, despite evidence that challenges the usefulness of routine MRI and the surgical interventions it may trigger, according to the authors.
"The worry is that many people will not benefit from the surgery, so heading in this direction is concerning," said senior author Laurence Baker, PhD, professor of health research and policy at Stanford University in Stanford, Calif.
In the study, Baker and first author Jacqueline Baras correlated areas with high numbers of MRI machines to an increased likelihood that MRI exams will be performed on new lower-back pain patients. In turn, high local MRI availability correlates with increased rates of lower-back surgery.
"It is important that policymakers recognize that infrastructure matters, and that the number of MRI machines in any particular area may affect the volume and quality of healthcare that patients receive," said Baras, a Stanford medical student with a master's degree in health services research.
While MRI exams visualize the internal structures and allow doctors to rule out some specific causes of back pain, the studies may also detect anomalies unrelated to back pain, prompting doctors to perform surgery that may not benefit the patient, the authors wrote.
To determine how MRI technology influences patient treatment, the researchers collected data on traditional Medicare patients who received care for nonspecific lower-back pain from 1998 through 2005. Patient data were linked with the number of MRI machines in the area. The areas of MRI availability were then divided into four groups, from high to low, and the incidence of MRI scans and surgeries were determined in each group.
The researchers projected that in 2004 there would have been 5.4 percent fewer lower-back MRI exams and 9 percent fewer back surgeries if all Medicare patients reporting new-onset lower-back pain had been living in the areas of lowest MRI availability.
According to the authors, two-thirds of the MRI scans that appear to result from increased availability happened within the first month of onset. Clinical guidelines recommend delaying MRI use until four weeks after onset, during which time most lower-back pain patients show spontaneous improvement.
"Not only are patients in high-availability areas getting more MRIs, but they are getting them earlier," said Baras.
Between 2000 and 2005, U.S. MRI availability more than tripled, from 7.6 machines per one million persons to 26.6 machines, Baras and Baker said. Each machine costs more than $2 million and one lower-back scan costs $1,500. Increased rates of scans and surgeries are increasing the cost to treat lower-back pain, they said.
Doctors and patients face difficult decisions when using medical equipment, such as MRI systems. "The big issue is how we handle new and exciting technologies in ways that allow us to reap the benefits of medical advances, without letting all of our new things generate waste or, worse, actual reductions in patient well-being," said Baker.
John Birkmeyer, MD, professor of surgery and a health policy researcher at the University of Michigan in Ann Arbor, who was not involved in the study, said the research confirms fears that greater access to MRI technology leads to more back surgeries.
"The net result is increased risks of unnecessary surgery for patients and increased costs for everybody else," Birkmeyer said.